World powers voiced deep concern Wednesday over Iran's announcement that it had successfully enriched uranium to make nuclear fuel, describing the move in unison as a "step in the wrong direction."
The phrase was used verbatim by officials from France, Germany, Russia and the United States, indicating a rare international consensus disapproving of Iran's latest act of brinkmanship.
But differences remained over what should happen next, with Washington demanding "strong steps" from the UN Security Council and Beijing, which wields a veto on the body, insisting talk of sanctions was unhelpful.
US Secretary of State Condoleezza Rice stopped short of calling for an emergency meeting of the Security Council to consider enforcement action right away.
But she made clear that when the 15-member council next discusses Iran after the expiry of an April 28 ultimatum for it to halt enrichment activity, the United States would expect action.
"I do think that the Security Council will need to take into consideration this move by Iran and that it will be time, when it reconvenes on this case, for strong steps to make certain that we maintain the credibility of the international community on this issue," she said.
The White House said sanctions against the Islamic regime would certainly be one of the options on the table at the meeting.
The United States has been prodding the Security Council to take a tough stand, including possible sanctions, but has run into opposition from both Beijing and Moscow, which also wields a veto.
Russia, which is involved in building Iran's first nuclear reactor, called President Mahmoud Ahmadinejad's announcement "a step in the wrong direction" and urged Iran to suspend all uranium enrichment activity.
But Foreign Minister Sergei Lavrov strongly opposed the use of force after US media reports over the weekend suggested Washington was considering military action.
"I am convinced that there can be no resolution of the problem through use of force... Practically all European countries are in solidarity with Russia" in this regard, he said.
Chinese ambassador Wang Guangya, who chairs the Security Council this month, expressed "concern" at the Iranian announcement but reiterated Beijing's opposition to sanctions.
"Military and other sanctions will not be helpful under the current circumstances," he said.
UN chief Kofi Annan declined to give up hope of a negotiated settlement, expressing hope that International Atomic Energy Agency head Mohamed ElBaradei will manage to persuade Iran to return to talks when he visits Tehran Thursday.
"I hope he will be able to convince the Iranian partners to come back to the table," Annan said.
"Yes, they have pursued their research. But I hope they will be able to come back to the table and work with the international community to find a negotiated solution."
The 25-nation European Union said the latest announcement from Iran went in the "wrong direction" but added it should not change the April 28 deadline already agreed by the international community for Tehran to comply.
"This announcement is very bad news, but the timing of action by the international community remains that agreed by the UN Security Council," said Cristina Gallach, spokeswoman for EU foreign policy chief Javier Solana.
Britain, one of three EU countries with France and Germany which had been trying to negotiate a voluntary freeze on enrichment activity by Iran, described the latest announcement as "deeply unhelpful".
"I call upon Iran to suspend its activities, begin the process of building confidence, and get back into negotiations," said Foreign Secretary Jack Straw.
"If Iran does not diplomatic measures."
The German government said it was "deeply concerned" by Iran's claim.
"We can only say that this is a further step in the wrong direction," said deputy government spokesman Thomas Steg.
The French government echoed Germany's stance.
"These recent declarations are rather a step in the wrong direction," said government spokesman Jean-Francois Cope.
Japan, the only nation to have suffered a nuclear attack, has maintained close relations with Iran before and after the 1979 Islamic revolution but still called on Iran to obey the international community.
Iran's move "goes against the messages of the United Nations Security Council and the International Atomic Energy Agency. It is extremely regrettable," Chief Cabinet Secretary Shinzo Abe told reporters.