Major powers will meet in London this week to discuss new sanctions on Iran amid a spat between Washington and the UN over Tehran's nuclear ambitions, US officials said on Tuesday.
The officials, who asked not to be named because they were not authorized to discuss the matter in public, said they expected the five permanent members of the UN Security Council plus Germany to meet toward the end of the week.
But Russian Foreign Minister Sergei Lavrov, visiting Tehran on Tuesday, suggested a unified approach was a way off, telling reporters "economic unilateral sanctions ... will not help the continued collective effort," an apparent reference to new US punitive measures announced last week.
Visiting Tehran two weeks ago, President Vladimir Putin also said Russia would not accept military strikes against Iran. Russia says dialogue is the way to ease tensions.
He also called on the Iranian leader to be "more active" in allaying the International Atomic Energy Agency's (IAEA) concerns over Tehran's controversial nuclear program.
Unilateral sanctions against Iran "are not helpful for the continuation of collective efforts" to resolve the dispute, Lavrov was quoted by Russia's Interfax news agency as saying.
Iranian President Mahmoud Ahmadinejad said in a speech on Tuesday that Iran would not retreat in the dispute and dismissed US offers of broader negotiations if Iran suspends its most sensitive atomic activities.
"This nation will not negotiate with anyone over its obvious and legal rights," he said. "... The Iranian nation does not need America."
This week's meeting of the P5+1 -- Britain, China, France, Russia, the US and Germany -- was to have taken place two weeks ago, but China pulled out after the US Congress honored the Dalai Lama.
Its purpose is to discuss a possible third UN Security Council resolution imposing sanctions against Iran for its refusal to suspend uranium enrichment. It was unclear whether the meeting would take place today or tomorrow.
The world's major powers agreed in late September to delay a vote on tougher sanctions on Iran until late this month at the earliest, depending on reports by the UN nuclear watchdog and an EU negotiator.
Russia and China opposed an early move to tighten economic sanctions, saying Tehran should be given more time to cooperate with IAEA to shed light on its past activities.
Agency chief Mohamed ElBaradei has annoyed Washington by suggesting its sometimes harsh stance toward Tehran was counter-productive. On Sunday, he urged Iran's critics to "stop spinning and hyping the Iranian issue."
Washington slapped new sanctions on Iran last week and recent months have seen somewhat belligerent rhetoric that has prompted speculation of possible US military action before US President George W. Bush steps down in January 2009.
Bush recently suggested that a nuclear-armed Iran could lead to World War III, but a White House spokeswoman said on Tuesday that was a "hypothetical situation" and the president was determined to resolve the standoff through diplomacy.
"There is no intention of bombing Iran," Dana Perino told reporters. "We are on a diplomatic track. We are working with our partners in the UN Security Council."