TEHRAN, Iran — An increasingly defiant Iran called yesterday for Europe to open talks on Tehran's intention to enrich uranium, and dismissed a veiled Bush administration warning of military action against Iranian nuclear operations as psychological warfare.

New Iranian President Mahmoud Ahmadinejad, meanwhile, named a hard-line Cabinet, a move that looked certain to intensify Iran's confrontation with the West.

While Iran says it would use enriched uranium only to power nuclear reactors for generating electricity, Tehran's past concealment of portions of its atomic program has created distrust in the West and strengthened suspicions in Washington that the material is meant for bombs.

The United States has stood aside while European governments negotiated with Iran. After prolonged talks with Britain, France and Germany during which Tehran put uranium conversion on hold, Iran rejected a package of aid measures this month, including offers of nuclear fuel in exchange for a promise to abandon plans for uranium enrichment.

Iran then restarted its Isfahan plant that converts uranium to gas, which is the last step in processing the radioactive ore before it can undergo enrichment to become reactor fuel or the material for nuclear weapons.

The U.N. nuclear-watchdog agency responded with a resolution Thursday urging the Iranians to again put the process on hold. Diplomats familiar with the International Atomic Energy Agency's (IAEA) proceedings said Iran was given a Sept. 3 deadline to halt or face possible referral to the U.N. Security Council for consideration of sanctions against its struggling economy.

Tehran hotly rejected the resolution and said yesterday there was nothing more to talk about on the conversion issue.

"The Isfahan issue is over," Mohammad Saeedi, the deputy head of Iran's Atomic Energy Organization, told state television.

"What is left on the table for discussion is Natanz," where Iran has built a uranium-enrichment plant.

"We definitely have plans for Natanz in the near future," Saeedi said, without offering any details.

Foreign Ministry spokesman Hamid Reza Asefi said Iran had not decided to begin uranium enrichment, but added: "Europe's behavior will heavily influence the decision."

Iran's chief delegate to the IAEA, Sirus Nasseri, indicated Thursday that any talks about enrichment would be about setting safeguards for operations at Natanz, to reassure those with suspicions, but not about closing the plant.

President Bush initially had said he was heartened by Iran's hinted readiness for additional talks on its nuclear program even as it rejected the European aid offer. But on Friday, after Iran became increasingly defiant, Bush said in an interview with Israeli TV that "all options are on the table" if Iran refused to comply with international demands.

That prompted Asefi to notch up the rhetoric yesterday, warning against any attack.

Further complicating relations with the West, Iranian President Ahmadinejad picked 21 hard liners to head government ministries. The parliament was expected to quickly approve the nominees.

The proposed foreign minister, Manouchehr Mottaki, has criticized the nuclear negotiations with Europe and called for Iran to refuse to make concessions. Several other nominees have ties to the Revolutionary Guards and security agencies, which also take a hard line on maintaining the country's nuclear program.

The new Cabinet also was seen as unsympathetic to the democratic and social reforms pushed by the previous government of President Mohammad Khatami, who tried to build bridges to the West.

"The list means Iran will behave more secretly in its dealings, both with the nation and the international community," said Saeed Madani, a political scientist.

In Washington, Sen. John McCain, R-Ariz., a member of the Senate Armed Services Committee, backed President Bush yesterday, saying the United States must keep open a military option.