The EU's foreign policy chief Catherine Ashton said on January 22 the Iran Six of negotiators were 'disappointed' after two-day talks ended with no breakthrough.

"That Iranian issue is difficult and sensitive - it cannot be solved through one or two meetings, only talks and mutual understanding can provide a lasting solution to the Iranian nuclear issue," spokesman Hong Lei said.

The Iran Six, which comprises Russia, the United States, China, Britain, France and Germany, has been trying since 2003 to convince Iran to halt its uranium enrichment program and to alleviate concerns about its nuclear ambitions.

The meeting of the Iran Six in Istanbul saw no progress with Tehran rejecting calls to cease uranium enrichment and allow improved UN monitoring of Iran's nuclear activities.

The EU foreign policy chief said no new negotiations were planned and no date for another meeting had been set.

However, earlier Turkish media said, citing Iranian representatives, that the talks will be continued.

World powers suspect Iran of pursuing a secret nuclear weapons program, but the Islamic Republic insists it needs nuclear power solely for civilian purposes.