The European Union issued a new demand Friday for Iran to return to international negotiations over its nuclear program, warning that a confrontation and tougher sanctions could be ahead if the standoff continued.

Swedish Foreign Minister Carl Bildt, who was chairing two-day talks among EU's foreign ministers, said the bloc was keen to restart such talks despite the political turmoil in Iran.

"We have a very generous offer on the table," Bildt said. "We want cooperation with Iran on quite a number of things, including the development of civilian nuclear technology."

Bildt, whose country holds the EU presidency, warned that Iran could not continue to ignore appeals over its nuclear enrichment program.

"If they are willing to engage with us, we are ready to cooperate with them. If they decide to go for confrontation, then confrontation will happen," Bildt said.

The 27-nation EU, the U.S. and others fear Iran is moving to develop nuclear warheads, allegations Iranian leaders reject.

Tehran insists its enrichment program is geared only toward generating fuel to produce nuclear energy, not nuclear arms.

EU foreign policy chief Javier Solana said he has been trying to get in contact with Iranian counterparts over comments made by Iran's nuclear negotiator, Saeed Jalili, that Iran would present new proposals.

Envoys from Germany, France, Britain, Russia, China and the U.S. met in Frankfurt on Wednesday and urged Iran to agree to new talks before the U.N. General Assembly meets later this month in New York. They plan to meet again in New York.

British Foreign Secretary David Miliband said Friday the EU and others were "very clear about commitments to sanctions and other actions" if Iran does not cooperate fully with the U.N.'s atomic energy agency.

He said the political instability caused by protests against the re-election of Iranian President Mahmoud Ahmadinejad in the wake of June's presidential vote was not an excuse to set aside the nuclear issue.

Miliband suggested Iran make its intentions known soon.

"We are coming into a season of international meetings ... we need a response from the Iranians," Miliband said.

EU officials acknowledged that the appointment of Ahmadinejad's new Cabinet was "complicating" efforts to get Iran back to negotiations. They spoke on condition of anonymity due to the sensitivity of the issue.

Ahmadinejad received a broad mandate on Thursday by Iran's parliament backing his main Cabinet choices, including a suspected mastermind in the 1994 bombing of an Argentine Jewish center that killed 85 people.

Iran has defied three sets of U.N. Security Council sanctions aimed at pressuring it to mothball its uranium enrichment. It also is resisting an IAEA probe into reports it had drafted plans and conducted experiments for a nuclear weapons program.