The United States and the European Union say they hope that stalled nuclear talks between Iran and world powers can start again soon.
EU foreign policy chief Catherine Ashton said that any fresh talks must focus exclusively on Tehran's nuclear program.
State Department spokesman Philip Crowley said the United States remains "fully prepared" to resume talks among six major powers and Iran to resolve Western questions about the purpose of Tehran's nuclear program.
"As we desired last year and as we repeat here -- we are interested in a process, more than one meeting, where we can begin to engage in, and hopefully answer, many of the questions that the international community has,” Crowley said.
The U.S. and its allies suspect that Iran intends to use enriched uranium for nuclear weapons.
This is rejected by Iran, which says its uranium enrichment program is aimed at peaceful energy generation.
Talks between Iran and the P5+1 group -- the five permanent members of the UN Security Council: the United States, Britain, France, Russia and China -- as well as Germany, stalled last October, leading to a toughening of UN sanctions against the Islamic Republic in June.
Negotiations have previously focused on Iran curbing its uranium enrichment in exchange for fuel for a Tehran reactor that produces medical isotopes.
Uranium enrichment is a process that can produce fuel for nuclear reactors or, if carried out to a much higher degree, can produce material for atomic bombs.
compiled from agency reports