Iranian officials said this week that Istanbul would be the site for negotiations with the U.N. Security Council five permanent members -- the United States, Russia, China, Britain, France -- plus Germany next weekend in Istanbul. A second round of talks would be later this year in Iraq.
The Iranian government had expressed reservations about Istanbul, saying it was frustrated that Turkey played host to a so-called Friends of Syria meeting. Ankara also received praise for Washington for taking a modest step away from Iranian crude oil.
Turkish Prime Minister Recep Tayyip Erdogan expressed frustration over Iran's various statements on the venue for multilateral nuclear negotiations.
"We have to be honest," he was quoted by Turkish news service Today's Zaman as saying. "Because of the lack of honesty they are continually losing their international prestige."
Turkish Foreign Minister Ahmet Davutoglu added that Ankara was interested in a Middle East free of nuclear weapons and weapons of mass destruction.
Iran is suspected of pursuing the technology needed to manufacture a nuclear weapon. The Iranian government maintains its nuclear program is for peaceful purposes.