Free Syrian Army fighters move through a hole in a wall in Khan al-Assal on Monday, July 22, after seizing the town. Tensions in Syria flared in March 2011 during the onset of the Arab Spring, escalating into an ongoing civil war. Click through to view the most compelling images taken since the start of the conflict. A rebel fighter walks past swings in a deserted playground in Deir al-Zor, Syria, on Sunday, July 21. A rebel fighter speaks with a fellow fighter through a hole in a wall in Deir al-Zor on July 21. A Free Syrian Army fighter casts a shadow on a wall as he carries his weapon in a shelter in Deir al-Zor on Thursday, July 18. Yahya Sweed, 13, is comforted by his father as he lies on a bed in Kfar Nubul on Tuesday, July 16. The boy was injured by shrapnel, resulting in the amputation of his right leg. A rebel fighter naps in a trench about 300 feet from the Syrian government forces' positions along the highway connecting Idlib with Latakia on Monday, July 15. A rebel fighter uses a hole in the wall of a destroyed school to aim at Syrian government forces in the Izaa district of Aleppo on Sunday, July 14. A Free Syrian Army fighter uses a mirror to scope out snipers loyal to Syrian President Bashar al-Assad in Aleppo on Friday, July 12. A Free Syrian Army fighter stands over a boy who was injured during shelling in Al-Bara on Monday, July 8. Members of the Free Syrian Army fire a homemade rocket toward regime forces in Deir al-Zor on Sunday, June 16. Syrian rebels leave their position in the northwestern town of Maaret al-Numan on Thursday, June 13. The White House said that the Syrian government has crossed a "red line" with its use of chemical weapons and announced it would start arming the rebels. Forces loyal to Syrian President Bashar al-Assad are seen near Qusayr on Thursday, May 30. Syrian rebels take position in a house during clashes with regime forces in the old city of Aleppo on May 22. Syrian army soldiers take control of the village of Western Dumayna north of the rebel-held city of Qusayr on Monday, May 13. Syrian troops captured three villages in Homs province, allowing them to cut supply lines to rebels inside Qusayr town, a military officer told AFP. Rebel fighters fire at government forces in the northern Syrian city of Aleppo on Sunday, May 12. Searchers use a flashlight as they look for survivors among the rubble created by what activists say was a missile attack from the Syrian regime, in Raqqa province, Syria, on April 25. A Kurdish fighter from the "Popular Protection Units" (YPG) takes position inside a building in the majority-Kurdish Sheikh Maqsood area of Aleppo, on Apri. 21. People walk past destroyed houses in the northern Syrian town of Azaz on Sunday, April 21. Free Syrian Army fighters take positions prior to an offensive against government forces in the Khan al-Assal area, near Aleppo on Saturday, April 20. Men inspect damage at a house destroyed in an airstrike in Aleppo on April 15. Syrian and Kurdish rebel fighters walk in the Sheikh Maqsud district of Aleppo on April 14. A female rebel monitors the movement of Syrian government forces in Aleppo's Sheikh Maqsud neighborhood on Thursday, April 11. A rebel runs to avoid sniper fire from Syrian government forces in Aleppo on April 11. Syrian rebels observe the movement of Syrian government forces around Al-Kendi hospital in Aleppo on Wednesday, April 10. Rescue teams and security forces check out the scene of a deadly car bomb explosion in Damascus on April 8. The fighting has taken a toll on buildings in Aleppo's Saladin district, seen here on April 8. A Syrian rebel runs for cover in Deir ez-Zor on April 2. A rebel checks for snipers across the street toward the Citadel in Aleppo, Syria, on Saturday, March 30, in this photo taken by iReporter Lee Harper. A Free Syrian fighter mourns the death of a friend in Aleppo on March 30, in this photo taken by iReporter Lee Harper. A Syrian opposition fighter runs for cover from Syrian army snipers in Aleppo on Wednesday, March 27. A Syrian girl covers her face to protect herself from fumes as a street covered with uncollected garbage is fumigated in Aleppo on Sunday, March 24. A Syrian man and his family drive past damaged buildings in Maarat al-Numan, on Wednesday, March 20. Syrians carry the body of a Syrian army soldier during a funeral ceremony in Idlib province on Tuesday, March 19. Syrian rebels take position in Aleppo, the largest city in the country, on March 11. Syrian men search for their relatives amongst the bodies of civilians executed and dumped in the Quweiq River on March 11. A Free Syrian Army fighter looks back as smoke rises during fighting between rebel fighters and forces loyal to Syria's President Bashar al-Assad on the outskirts of Aleppo on Saturday, March 2. Residents read Shaam News newspapers published by the Free Syrian Army in Aleppo on March 2. A member of the Free Syrian Army reacts to the death of a comrade who was killed in fighting, at Bustan al Qasr cemetery in Aleppo on Friday, March 1. A rebel fighter throws a home-made grenade at Syrian government forces in Aleppo on February 16. A member of the Free Syrian Army stands with his weapon as he looks at a rainbow in Aleppo on February 16. A Syrian woman looks through a bus window in Aleppo on February 14. Free Syrian Army fighters walk through a dust-filled stairwell in Damascus on February 7. A Syrian rebel gestures at comrades from inside a broken armored personnel carrier in Al-Yaqubia on February 6. A rebel fighter throws a hand grenade inside a Syrian Army base in Damascus on February 3. People stand in the dust of a building destroyed in an airstrike in Aleppo, Syria on February 3. Free Syrian Army fighters run as they enter a Syrian Army base during heavy fighting in the Arabeen neighborhood of Damascus on February 3. An unexploded mortar shell fired by the Syrian Army sits lodged in the ground in Damascus on January 25. Fighters from Fateh al Sham unit of the Free Syrian Army fire on Syrian Army soldiers at a check point in Damascus on January 20. A Free Syrian Army fighter walks between buildings damaged during Syrian Air Force strikes in Damascus on January 19. A Syrian rebel fighter tries to locate a government jet fighter in Aleppo on January 18. Syrian rebels launch a missile near the Abu Baker brigade in Albab on January 16. A Syrian boy walks near rubbish next to tents at a refugee camp near the northern city of Azaz on the Syria-Turkey border, on January 8. Syrians look for survivors amid the rubble of a building targeted by a missile in Aleppo on January 7. A father reacts after hearing of a shelling by forces loyal to Syria's President Bashar al-Assad in Aleppo on January 3. A patient smokes a cigarette at Dar Al-Ajaza psychiatric hospital in Aleppo on December 18, 2012. The psychiatric ward, housing around 60 patients, has lacked the means to function properly since fighting broke out there in July. Syrians mourn a fallen rebel fighter at a rebel base in the al-Fardos area of Aleppo on December 8. Members of Liwa (Brigade) Salahadin, a Kurdish military unit fighting alongside rebel fighters, monitor the area in the besieged district of Karmel al-Jabl in Aleppo on December 6. A member of Liwa Salahadin aims at a regime fighter in the besieged district of Karmel al-Jabl in Aleppo on December 6. Two young boys sit underneath a washline in a refugee camp on the border between Syria and Turkey near Azaz on December 5. The bodies of three children, who were allegedly killed in a mortar shell attack that landed close to a bakery in Aleppo, on December 2, are laid out for identification by family members at a makeshift hospital at an undisclosed location of the city. Smoke rises in the Hanano and Bustan al-Basha districts in Aleppo on December 1 as fighting continues through the night. Damaged houses in Aleppo are seen after an airstrike on November 29. A Syrian rebel mourns the death of a comrade in Maraat al-Numan on November 20. Syrians protesters stand on Assad's portrait during an anti-regime demonstration in Aleppo on November 16. A Syrian rebel takes cover during fighting against Syrian government forces in Aleppo on November 15. Syrian opposition fighter Bazel Araj, 19, sleeps next to his pistol in Aleppo on November 11. A rebel fighter fires at a Syrian government position in Aleppo on November 6. A Syrian rebel leaps over debris left in the street while running across a "sniper alley" near the Salahudeen district in Aleppo on November 4. Rebels hold their position in the midst of a battle on November 3 in Aleppo. A man cries while being treated in a local hospital in a rebel-controlled area of Aleppo on October 31. A man is treated for wounds after a government jet attacked the Karm al-Aser neighborhood in eastern Aleppo on October 31. A Syrian rebel interrogates a handcuffed and blindfolded man suspected of being a pro-regime militiaman in Aleppo on October 26. Smoke rises from a fuel station following a mortar attack as Syrian women walk on a rainy day in the Arqub neighborhood of Aleppo on October 25. A Syrian rebel fires at an army position in the Karm al-Jabal district of Aleppo on October 22. A wounded Syrian boy sits on the back of a truck carrying victims and wounded people to a hospital following an attack by regime forces in Aleppo on October 21. A man lies on the ground after being shot by a sniper for a second time as he waits to be rescued by members of the Al-Baraa Bin Malek Battalion, part of the Free Syria Army's Al-Fatah brigade, in Aleppo on October 20. Syrian army soldiers run for cover during clashes with rebel fighters at Karam al-Jabal neighborhood of Aleppo on October 20. Smoke rises after a Syrian Air Force fighter jet fired missiles at the suburbs of the northern province of Idlib on October 16. A Syrian opposition fighter stands near a post in Aleppo on October 11. A Syrian man mourns the death of his father, who was killed during a government attack in Aleppo on October 10. A rebel fighter is carried by his friends and laid on a gurney to be treated for gunshot wounds sustained during heavy battles with government forces in Aleppo on October 1. Syrian rebels help a wounded comrade to an Aleppo hospital after he was injured in a Syrian army strike on September 18. Free Syria Army fighters are reflected in a mirror they use to see a Syrian Army post only 50 meters away in Aleppo on September 16. A Syrian man carrying grocery bags tries to dodge sniper fire as he runs through an alley near a checkpoint manned by the Free Syria Army in Aleppo on September 14. A woman walks past a destroyed building in Aleppo on September 13. Free Syrian Army fighters battle during street fighting against Syrian army soldiers in Aleppo on September 8. A Syrian man wounded by shelling sits on a chair outside a closed shop in Aleppo on September 4. A woman sits in her wheelchair next to her house, damaged by a Syrian air raid, near Homs on August 26. Members of the Free Syrian Army clash with Syrian army soliders in Aleppo's Saif al-Dawla district on August 22. A man mourns in front of a field hospital on August 21 in Aleppo. Wounded civilians wait in a field hospital after an air strike on August 21 in Aleppo. People pray during the funeral of a Free Syrian Army fighter, Amar Ali Amero, on August 21. A man cries near the graves of his two children killed during a recent Syrian airstrike in Azaz on August 20. A Syrian woman holds her dead baby as she screams upon seeing her husband's body being covered following an airstrike by regime forces on the town of Azaz on August 15. A Syrian rebel runs in a street of Selehattin during an attack on the municipal building on July 23. Syrian rebels hunt for snipers after attacking the municipality building in the city center of Selehattin on July 23. Members of the Free Syrian Army's Mugaweer (commandos) Brigade pay their respects in a cemetery on May 12 in Qusayr. Syrian rebels take position near Qusayr on May 10. A Free Syrian Army member takes cover in underground caves in Sarmin on April 9. Rebels prepare to engage government tanks that advanced into Saraquib on April 9. Men say prayers during a ceremony in Binnish on April 9. A young boy plays with a toy gun in Binnish on April 9. A Free Syrian Army rebel mounts his horse in the Al-Shatouria village near the Turkish border in northwestern Syria on March 16, a year after the uprising began. Syrian refugees walk across a field before crossing into Turkey on March 14. A rebel takes position in Al-Qsair on January 27. A protester in Homs throws a tear gas bomb back towards security forces, on December 27, 2011. A man stands under a giant Syrian flag outside the Umayyad Mosque in Damascus on December 24, 2011. A member of the Free Syrian Army looks out over a valley in the village of Ain al-Baida on December 15, 2011. Members of the Free Syrian Army stand in an valley near the village of Ain al-Baida, close to the Turkish border, on December 15, 2011. Displaced Syrian refugees walk through an orchard adjacent to Syria's northern border with Turkey on June 14, 2011, near Khirbet al-Jouz. A Syrian man holds up a portrait of President Bashar al-Assad during a rally to show support for the president in Damascus on April 30, 2011. Syrians rally to show their support for President Bashar al-Assad in Damascus on April 30, 2011. A screen grab from YouTube shows thick smoke rising above as Syrian anti-government protesters demonstrate in Moaret Al-Noman on April 29, 2011. A screen grab from YouTube shows Syrian anti-government protesters run for cover from tear gas fired by security forces in Damascus on April 29, 2011, during the "Day of Rage" demonstrations called by activists to put pressure on al-Assad. Syrians wave their national flag and hold portraits of al-Assad during a rally to show their support for their leader in Damascus on March 29, 2011. A woman sits by the hospital bed of a man allegedly injured when an armed group seized rooftops in Latakia on March 27, 2011, and opened fire at passers-by, citizens and security forces personnel according to official sources. Syrian protesters chant slogans in support of al-Assad during a rally in Damascus on March 25, 2011.
- NEW: Congressman worries about U.S. arms going to future enemies
- White House spokesman says military aid is to keep the Syrian opposition going
- Despite concerns, a House committee chairman offers support for the plan
- Joint Chiefs Chair Gen. Martin Dempsey: U.S. military involvement could cost billions
Washington (CNN) -- Reluctant approval from Congress for providing military support to Syrian rebels allows the Obama administration to move forward with plans first announced almost six weeks ago.
White House spokesman Jay Carney told reporters on Tuesday that the goal of the military aid expected to include small arms, ammunition and perhaps anti-tank weapons is to keep the Syrian opposition going against forces aligned with President Bashar al-Assad's regime.
Noting al-Assad's forces have been helped by Hezbollah in Lebanon as well as Iran, Carney said Syrian rebels need the help of the United States and allied nations to withstand an increased assault.
"The aid is intended to help the opposition resist Assad and eventually prevail," Carney said, adding that any resolution of Syria's civil war will require a political transition.
His comment appeared intended to soften any expectations that the rebels could topple the regime by military means alone.
A source speaking on condition of being identified only as an official said Monday that President Barack Obama can begin acting on plans for increased Syrian aid first made public last month now that concerns of Congress had been resolved.
House Intelligence Committee Chairman Rep. Mike Rogers said Monday that his panel agreed to the administration's plan for military aid despite reservations about its chances for success.
"After much discussion and review, we got a consensus that we could move forward with what the administration's plans and intentions are in Syria consistent with committee reservations," the Michigan Republican said.
At a congressional hearing on Tuesday on next year's defense budget, GOP Rep. Rich Nugent of Florida said he worried that arming Syria rebels today could mean his sons in the military might face those weapons in the future, if they fall into the wrong hands.
"We want to make sure that we don't put our sons or daughters in any jeopardy particularly as it relates to arming those that we have no idea who they are," Nugent said.
The Obama administration has been reluctant to enter another military engagement, but announced on June 13 that it would provide military support to rebel fighters because al-Assad's forces had used chemical weapons.
Its plans so far stop short of calls by some in Congress, such as veteran Republican Sen. John McCain of Arizona, to establish a "no-fly" zone over Syria.
In a letter released Monday, Joint Chiefs Chairman Gen. Martin Dempsey warned U.S. military involvement would likely cost billions of dollars and include a range of risks for the forces involved.
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"It is no less than an act of war," Dempsey wrote to Democratic Sen. Carl Levin of Michigan, who chairs the Senate Armed Services Committee.
The United States has learned from the past 10 years "that it is not enough to simply alter the balance of military power without careful consideration of what is necessary in order to preserve a functioning state," Dempsey's letter said in apparent reference to wars in Iraq and Afghanistan.
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McCain, who has long advocated arming Syrian rebels, said Tuesday he was disappointed by Dempsey's letter.
"Most military experts that I know totally disagree" with Dempsey's assessment of the size of the task and U.S. capabilities, McCain said. "The question should be is the status quo acceptable and obviously that is not."
Last month, McCain called for taking out al-Assad's air assets to create a safe zone for the Syrian opposition.
"I know that we have the military capability to impose a 'no-fly' zone, to crater their runways and their fixed installations where fuel and parts are, and establish a 'no-fly' zone with Patriot missiles," McCain said in June.
"And if we can't do that, then the question ought to be asked to the American taxpayer, to the Pentagon, 'What in the world are we wasting tens of billions of dollars for defense for if we can't even take care of this situation?'" McCain said.
Dempsey: Syria intervention is "act of war" that could cost billions
More than 100,000 people have been killed since the Syrian crisis began in March 2011, while refugees fleeing the conflict threaten to overtax government services and destabilize neighboring Jordan.
In Washington, Secretary of State John Kerry met Tuesday with U.N. agencies and other international aid organizations to discuss challenges to addressing what he called a humanitarian crisis.
"We are having a very difficult time being able to access people, move people directly and protect people so we intend to have a very solid, in-depth discussion today about creative ways that we can meet our obligations to human beings who are in huge danger and distress," Kerry said.
He noted his visit this week to a Syrian refugee camp in Jordan where he said he witnessed "the dramatic and unbelievably moving ways in which people are separated from homes and family, so many people murdered and killed in massacres and yet somehow these people try to pull themselves together."
Sources: U.S. to send small arms, ammo to Syrian rebels
CNN's Jamie Crawford contributed to this report.