UNITED NATIONS - Negotiations on an Iran sanctions resolution were unexpectedly postponed Tuesday because of Russia's anger at the United States for raising the plight of an opposition leader in Belarus in the UN Security Council.

Russian Atomic Agency Chief Sergei Kiriyenko, left, shakes hands with Iranian Foreign Minister, Manouchehr Mottaki, during their meeting in Tehran, Iran, Monday, Dec. 11, 2006. Russia's nuclear chief will arrive in Tehran Monday for talks on finishing the construction of Iran's first nuclear power plant, being built by Russians in the south of the country. [AP]

Belarus, an authoritarian former communist state that has close ties to Russia, is not on the agenda of the UN's most powerful body. Russia's Ambassador Vitaly Churkin strongly objected when senior US diplomat William Brencick brought up the 54-day hunger strike of jailed former Belarusian opposition presidential candidate, Alexander Kozulin, council diplomats said.

The five veto-wielding council members - the US, Russia, China, Britain and France - along with Germany had been scheduled to meet soon after to discuss Russian amendments to a revised European draft resolution on Iran. But because of the diplomatic tiff over Belarus, the meeting was put off.

"It wasn't the best timing by the US," said Britain's UN Ambassador Emyr Jones Parry.

The Europeans circulated a revised text on Friday in a bid to win backing from Russia and China, and Churkin said after talks Monday he was pleased with the direction of the negotiations though specific points still needed to be worked out.

A US official said Washington felt it was important to raise the issue of Kozulin in the Security Council because of US concerns for freedom of political expression and democracy, especially in the heart of Europe.

"We raised this issue and our goal was to highlight the plight of this individual and what it means for the state of democracy in this country," the official said, speaking on condition of anonymity because the council meeting was closed.

Kozulin, who ended his hunger strike on Tuesday, has been jailed since March when he led a protest march following presidential elections in which he was one of three candidates challenging authoritarian President Alexander Lukashenko.

Kozulin had been on hunger strike to protest his sentencing in June to five and a half years in prison for organizing the unsanctioned protest.

Lukashenko has ruled Belarus since 1994, quashing dissent and maintaining power through elections that have been dismissed by critics abroad and at home as illegitimate.