The United States, France, Britain, and Germany have condemned Iran's decision
to start enriching uranium at an underground facility after a closed-door meeting of the UN Security Council.
Western envoys said there was little chance the 15-nation council would impose a fifth round of UN sanctions on the Iranians anytime soon due to resistance from veto powers Russia and China.
"It's a worrying development," French Deputy Ambassador Martin Briens told reporters about Iran's enrichment work after
the council meeting.
He added that Tehran's new move was a violation of multiple resolutions of the UN Security Council and the International Atomic Energy Agency's board of governors.
Iran appealed to the Security Council and UN Secretary-General Ban Ki-Moon to condemn the latest assassination
of an Iranian nuclear scientist.
Mostafa Ahmadi Roshan, who worked at the Natanz uranium enrichment facility, died along with the driver of his car in a drive-by motorcycle bomb attack in Tehran on January 11.
The United States has condemned the killing of the scientist.
National Security Council spokesman Tommy Vietor said the U.S. "had absolutely nothing to do" with the attack.
Japan has said it will start to reduce oil imports from Iran, in support of U.S. sanctions against Tehran over its nuclear program.
Finance Minister Jun Azumi made the announcement after a one-hour meeting with visiting U.S. Treasury Secretary Timothy Geithner.
"Nuclear development is something that the world cannot shut its eyes to, so we understand the United States' position," Azumi said. "As for the remaining 10 percent share [of crude oil imports from Iran], we plan to gradually reduce that in a concrete manner."
Azumi told a press conference after the meeting that Iran's "nuclear development problem can't be ignored by the world."
Japan imports about 10 percent of its oil from Iran.
Meanwhile, the secretary of Russia's Security Council, Nikolai Patrushev, has warned that military escalation is likely in Iran, with a "real danger" of a U.S. strike.
Patrushev said in an interview on the website of the daily “Kommersant” that "there is a likelihood of military escalation of the conflict, and Israel is pushing the Americans towards it.”
Patrushev said that "nobody has proved the existence of a military component of Iran's nuclear program."
compiled from agency reports