"For the EU, diplomacy remains the No. 1 way forward," said Finnish Foreign Minister Erkki Tuomioja, whose country holds the EU presidency.
He said "this is not the time or place" for the international community to hit Iran with sanctions.
Iran defied a Thursday U.N. Security Council deadline to stop uranium enrichment, raising the prospect of U.N. economic and other sanctions. In Tehran, Iranian President Mahmoud Ahmadinejad reiterated that his country would not be bullied into giving up what he called Iran's right to nuclear technology.
U.S. President George W. Bush said Thursday that Iran has responded with defiance and delay to demands to stop enriching uranium.
Russia's Foreign Minister Sergey Lavrov said Friday that Moscow regrets Iran's decision — but wants to keep all options open, Russian news agencies said.
Tuomioja said if Iran indeed seeks negotiations, "then we have to see what the conditions are."
"We are still, all of us, wanting to engage Iran seriously," he said at a meeting of EU foreign ministers in Finland.
U.S. and other officials have said that no action will be sought against Tehran before EU foreign policy chief Javier Solana meets with Iran's atomic chief next week to seek a compromise.
Solana is to brief EU ministers on his conversation Thursday with Iran's top nuclear negotiator, Ali Larijani.
The U.N.'s International Atomic Energy Agency in Vienna confirmed Thursday that Tehran had not halted uranium enrichment as demanded by the Security Council, and said three years of IAEA probing had been unable to confirm "the peaceful nature of Iran's nuclear program" because of lack of cooperation from Tehran.
Iran denies it is trying to acquire atomic weapons in violation of its commitments under the Nuclear Nonproliferation Treaty. Tehran insists its nuclear program is peaceful, with the sole aim of producing electricity with nuclear reactors.
The Security Council voted July 31 to impose the Thursday deadline for Iran to suspend uranium enrichment and asked the IAEA to report on Tehran's compliance, dangling the threat of sanctions if Iran refused.