- Iran and six world powers are engaged in nuclear negotiations
- The talks are aimed at reaching a permanent deal on Tehran's nuclear program
- Kerry plans to speak with his German counterpart amid spying allegations
Kabul (CNN) -- U.S. Secretary of State John Kerry landed in Austria on Sunday for talks with six world powers and Iran on Tehran's nuclear program.
The world powers, including the United States, will join a final round of negotiations ahead of a July 20 deadline aimed at reaching a permanent deal on the future of Iran's nuclear program.
Iran's talks will comprise Germany plus the five permanent members of the United Nations Security Council -- the U.S., UK, France, China and Russia.
Tehran insists its ambitions are peaceful, but the world powers fear it plans to build nuclear weapons.
Kerry is due to speak in Vienna with his German counterpart, Frank-Walter Steinmeier, senior administration officials said. The foreign ministers' encounter will come amid a row over fresh spying allegations against the United States.
On Thursday, Germany's government asked America's top spy chief stationed in the country to leave.
This followed the revelation that two Germans -- one working at a German intelligence agency, the other in the Ministry of Defense -- are suspected of spying for the United States.
Kerry's stop in Austria follows an unannounced visit to Afghanistan amid growing division following the country's contested presidential runoff election.
After his visit, he announced that an audit of the disputed presidential election results will begin within a day in Kabul, and the two candidates will accept its determination of who won.
The inauguration of the new President, originally scheduled for August, will be postponed while the audit of votes cast for Abdullah Abdullah and Ashraf Ghani is conducted, Kerry said.
Despite efforts by the Taliban to disrupt the election, about 8 million Afghans voted in June 14. Provisional results showed Ghani ahead with roughly 56% support to 43% for Abdullah.
Kerry unveils audit for Afghan election 
Abdullah: Half of ballots 'suspicious' 
Could Afghanistan be the next Iraq? Both candidates have alleged vote fraud and manipulation during the runoff last month.
