VIENNA, Austria (AP) – Iran abruptly announced Wednesday that last-ditch talks on its disputed nuclear program were postponed, moving Tehran a step closer to U.N. sanctions after it defied a deadline to freeze uranium enrichment.

Russian Foreign Minister Sergey Lavrov, meanwhile, said any sanctions must exclude military force, suggesting that Moscow was contemplating the possibility of sanctions but remained opposed to harsh and quick punishment.

The talks between Iranian nuclear envoy Ali Larijani and European Union foreign policy chief Javier Solana had been tentatively set for Wednesday in Vienna as a final attempt to see if common ground could be found to start negotiations between Iran and the six nations that have been trying to persuade Iran to limit its nuclear program.

But while Mr. Solana had been ready to fly to the Austrian capital at short notice, the talks had been left hanging by uncertainty over whether Mr. Larijani would come.

“We will not have the meeting today in Vienna,” Ali Ashgar Soltanieh, the chief Iranian envoy to the International Atomic Energy Agency, told The Associated Press. “Both sides are arranging (a meeting) for a couple of days later.”

Mr. Solana’s office in Brussels, Belgium, had no immediate comment. But although Mr. Soltanieh said the decision to postpone any meeting had been mutual, it appeared that Iranian reluctance to attend had scuttled the chance of talks Wednesday.

Russia, along with China, has steadfastly opposed efforts by the United States and other Western nations to bring sanctions against Iran for its nuclear program. Washington says Tehran is seeking to build nuclear weapons; Tehran says its programs are for electricity generation.

Mr. Lavrov said the U.N. Security Council’s recent resolution on the issue holds out the possibility of further measures on Iran such as economic penalties, banning air travel or breaking diplomatic relations, but not the use of armed force.

“This article envisages measures to exert influence on a country that is not cooperating, including economic ones, but it is written unambiguously there that this excludes any kind of forceful measures of influence,” ITAR-Tass quoted him as saying.

Mr. Lavrov spoke to reporters in Cape Town, South Africa, where he was accompanying President Putin on a state visit.

American and European diplomats have said they are focusing at first on low-level punishment such as travel bans on Iranian officials or a ban on the sale of dual-use technology, to win backing from Russia and China. More extreme sanctions would be a freeze on Iranian assets or a broader trade ban, but those would likely be opposed by Russia, China and perhaps others, particularly since the trade ban could cut off badly needed oil exports from Iran.

Iran defied an Aug. 31 deadline by the U.N. Security Council to freeze uranium enrichment.

But the five permanent council members and Germany _ the six powers attempting to entice Iran into negotiating on its nuclear program _ had decided to hold off starting work on sanctions until the outcome of any talks between Mr. Solana and Mr. Larijani.

Senior negotiators of those six countries meet in Berlin on Thursday to plan strategy.

Looking ahead to those talks, Assistant Secretary of State Daniel Fried said he had no doubt “they will be very substantive and very serious.”

In Ankara, Turkey, Secretary-General Annan, whose visit to Tehran last week failed to budge the leadership on its refusal to give up enrichment, urged Iran “to do whatever it can to reassure the international community that indeed its intentions are peaceful.”

Mr. Soltanieh said “a procedural matter” had led to the postponement, but offered no details. In Tehran, Foreign Minister Manouchehr Mottaki said only the time and place of any meeting continued to be “under discussion by both sides.”

Iran’s unyielding stance appeared to be based on the calculation that sanctions will be opposed by Russia and China, both veto-wielding Security Council members that have major commercial ties with Iran. While skeptical that any new meeting between Solana and Larijani would yield success, the United States and key European allies Britain and France had agreed to wait for the result of any such talks in attempts to mollify Moscow and Beijing.

In Beijing China’s premier, Wen Jiabao, said that sanctions “may even prove counterproductive.”

But American officials on both sides of the Atlantic suggested the time had already come for punitive Security Council action.

State Department spokesman Sean McCormack said in Washington that the Security Council had made clear in a resolution that it was prepared to vote for sanctions if Iran failed to meet the Aug. 31 deadline to suspend enrichment.

And so, Mr. McCormack said Tuesday, the United States intended to proceed “down that pathway.”

In Vienna, Gregory L. Schulte, chief American delegate to the IAEA, accused Iran’s leaders of making “a strategic decision to acquire nuclear weapons,” adding: “The time has come for the Security Council to back international diplomacy with international sanctions.”

Iran insists it has a right to enrich for generation of nuclear power. But suspicions are growing it wants to develop the technology to enrich uranium to the weapons-grade level for the fissile core of nuclear warheads.

In a further sign of Tehran’s defiance, Iran’s parliament took the first step Tuesday toward blocking international inspection of the country’s nuclear installations in case of U.N. sanctions. The measure would need approval by other bodies before it could take effect.