Iran's army commander has warned the United States and other Western powers not to make any "stupid move" over Tehran's nuclear work, and suggested they would be surprised by Iran's military response if they attacked.

The comments by the commander-in-chief of the army, reported by newspapers on Saturday, were the latest in a series of defiant statements by Iran's leadership as the United Nations prepares to vote on new sanctions against the Islamic Republic.

Iran is embroiled in an escalating dispute over its uranium enrichment, which Iran says is for fuel for power generation but the West suspects is aimed at making nuclear bombs.

The United States says it would prefer a negotiated solution to the crisis, but has not ruled out military options.

Armed forces chief Ataollah Salehi said Iran's military was stronger now than when Iran fought against Iraq in 1980-88.

"And if our bullying enemies make a stupid move, they will certainly be surprised," the daily Siyasat-e Rouz quoted him as saying on Friday.

Military experts say Iranian forces are no technological match for the U.S. military but could still cause havoc in the Gulf and the narrow Strait of Hormuz, a choke point through which two-fifths of the world's traded oil passes.

A draft resolution agreed by the U.N. Security Council's five members with veto power -- the United States, France, Britain, China and Russia -- and Germany was sent to the 15-nation council on Thursday for a vote, expected next week.

It seeks new sanctions including an arms export ban and an expanded asset freeze list over Iran's refusal to suspend uranium enrichment.

Enriched uranium, can be used to generate electricity or, more highly enriched, to make nuclear bombs.

Major powers have demanded that Iran halt such nuclear work as a precondition for broader talks that they say would lead to major trade and diplomatic benefits for the oil-rich country.

But Iranian officials have insisted in recent days that they will not bow to pressure and abandon their atomic ambitions.

"Taking an inappropriate decision by passing a new (U.N.) resolution may bring all kinds of consequences," the IRNA news agency quoted Foreign Minister Manouchehr Mottaki as saying on Saturday.

"We still prefer cooperation and negotiation for reaching a political solution."

Russia urged the United States to show more flexibility toward Iran to solve the crisis.

"On North Korea, they were able to show flexibility, they were able to reach a compromise and got away from demands in the form of ultimatums," Foreign Minister Sergei Lavrov said.

"I think the same approach would help restart negotiations on the Iranian nuclear dossier as well," he said in Moscow.