Erdoğan told reporters on Thursday that Iran's proposal for a new venue was an untenable demand that would sabotage the planned talks. "The offer going round at the moment, Damascus or Baghdad, is a waste of time, it means it won't happen, because they know the other side won't come to Damascus or Baghdad," Erdoğan told a news conference in Ankara.
"[Iran] needs to be honest," Erdoğan said, adding that they are constantly losing prestige in the world by not being honest.
Turkish prime minister also added that Iran's language is not a diplomatic one and that speaking in that language would not fit to his ethics.
Iran has balked at having the negotiations in İstanbul because of Turkey's escalating pressure on the embattled regime of Syrian President Bashar Assad, a key Iranian ally.
Head of the parliamentary committee for national security and foreign policy, Alaeddin Boroujerdi, said on Thursday that he supported Baghdad as a venue, one of several alternative sites floated by Iran in recent days. Iraq's Shiite-led government has long-standing ties with Iran, and other sites mentioned by Iran - Syria, Lebanon or China - are also allies of Tehran.
Western officials have complained about Iran bargaining over the venue for this month's planned talks with world powers.
Earlier this week, Clinton said the talks would take place in İstanbul. Western officials have remained committed to Turkey as the host, although possible alternatives could be Switzerland or Vienna, the site of the UN nuclear watchdog agency. European envoys have taken the lead in trying to work out a location for the talks.
The last attempt at talks over Iran's nuclear ambitions quickly collapsed 14 months ago after Iran refused proposals that included freezing its uranium enrichment in exchange for delivery of reactor-ready fuel from outside the country. The West and others fear Iran could use its ability to make nuclear fuel to eventually develop atomic weapons. Iran says it only seeks reactors for energy and medical research.
After Erdoğan's comments it would appear even more unlikely the talks will be held in İstanbul, and the lack of a venue could throw into question whether the negotiations will take place at all.
"This meeting is not something that will win us any prestige and we are not after any such prestige. Iran would be the winners with us here. Why? Because we would put forward for them a just approach," Erdoğan said.