PARIS, Jan. 28 - President Bush´s second term has barely begun, and Iran is already shaping up as its most serious diplomatic challenge. But conflicting pronouncements by Mr. Bush and his national security team have left Iran frustrated and angry about the direction of American policy, and the Europeans more determined than ever to push Washington to embrace their engagement strategy.

To the outside world, the administration seems divided over whether to promote the overthrow of Iran´s Islamic Republic - perhaps by force - or to tacitly support the approach embraced by the Europeans, which favors negotiations and a series of incentives that would ultimately require American participation.

"You need to get everybody to read from the same page, the Europeans and the Americans," said Mohamed ElBaradei, head of the International Atomic Energy Agency, in an interview in Davos on Friday.

"This is not a process that is going to be solved by the Europeans alone," he added. "The United States needs to be engaged. If you continue to say they are going to fail before you give them a chance, it will be a self-fulfilling policy."

France´s foreign minister, Michel Barnier, echoed those remarks in an interview in Paris on Friday. "I cannot explain American policy to you," he said. "That would be French arrogance and I am not someone who is arrogant. But I think that the Americans must get used to the fact that Europe is going to act. And in this case, without the United States we run the risk of failure."

France, Germany and Britain - with European Union support - opened negotiations with Iran last month that could give Iran generous rewards on nuclear energy, trade and economic, political and security cooperation if Iran can provide guarantees that it is not developing a nuclear weapon.

The negotiations flow from Iran´s voluntary decision in November to temporarily freeze its programs to make enriched uranium, which can be used for producing energy or for making bombs.

Instead of embracing the initiative, Mr. Bush began his second term with a sweeping pledge to defend the United States and protect its friends "by force of arms if necessary" and a refusal to rule out military action against Iran.

In her Senate confirmation hearings as secretary of state, Condoleezza Rice did not say no when asked whether the goal of the United States was to replace the Islamic Republic in Iran.

Vice President Dick Cheney, too, has put Iran at the "top of the list" of the world´s trouble spots and suggested that Israel might attack Iran militarily because of its nuclear program. Those words, combined with a report in The New Yorker that secret Pentagon operations were under way in Iran to prepare target lists for possible military action, have left the impression - particularly in Tehran - that Iran may be the next Iraq.

"Madness," is how Iran´s president, Mohammad Khatami, described that approach, while his foreign minister, Kamal Kharrazi, dismissed the talk of a military strike as "psychological warfare."

Britain joined the American-led war in Iraq while France and Germany opposed it. But when it comes to Iran, the three European countries are unanimous in support of negotiations over any possible military plans by the United States or Israel.

"This is a hotbed region; the last thing we need is a military conflict in that region," Chancellor Gerhard Schröder of Germany said in Davos on Friday. "I´m very explicit and outspoken about this because I want everybody to know where Germany stands."

The British foreign secretary, Jack Straw, has also strongly criticized a possible military attack on Iran as "inconceivable." Mr. Straw told the BBC that the issue of a military option was not raised during his talks with Ms. Rice and other officials in Washington this week.

But European officials say the signals emanating from Washington have been inconsistent. At one point in her confirmation hearings, Ms. Rice suggested that the United States implicitly supported the European negotiating approach, saying the Bush administration is "trying to see" if it will produce concrete results, though she and other officials in Washington have bluntly told the Europeans they are skeptical.

Ms. Rice also repeated a threat to ask the Security Council for censure or possible sanctions against Iran, and specified that even a complete halt to Iran´s nuclear and missile programs would not translate into American support for a policy of engagement and incentives.

There were "other problems" that precluded such an approach: "terrorism, our past, their human rights record," she said.

Further complicating the picture is that in a news conference in late December, Mr. Bush uncharacteristically admitted the limits of American power. "We´re relying upon others, because we´ve sanctioned ourselves out of influence with Iran," he said, in reference to the fact that the United States has long banned most trade and investment with Iran and has no diplomatic relations with it.

The Europeans have made the determination that any negotiation that slows and perhaps eventually halts Iran´s nuclear program is better than the alternatives proposed by the United States.

"Is this approach free of risks? No," said Javier Solana, the European Union´s foreign policy chief, in a telephone interview. "Does it have a guarantee of success? No. But at this point in time it is the only game in town, no doubt about that. The other options are worse."

Some senior Iranian officials make the same point. "The West has suspicions about our nuclear program; we have suspicions of the Europeans," said M. Javad Zarif, the Iranian ambassador to the United Nations and a key negotiator with the Europeans, in a telephone interview. "We are eager to use any possible avenue to resolve those suspicions," Dr. Zarif said. "That´s why we have had the pragmatism to understand that the European game is a very serious game. Washington has yet to understand that the European game is the only game in town."

Thus far, the three sets of "working level" talks on nuclear, economic and technological cooperation and political and security cooperation have yielded no concrete results, European officials said.

On the contrary, in their meeting on Jan. 17, Iran insisted that it would never abandon its goal of "maintaining" its enrichment program, while the Europeans called such an approach "unacceptable," insisting on the ultimate permanent cessation of the program, one of the European participants in the meeting said.

Similarly, the most recent inspection team of the International Atomic Energy Agency, the United Nations´ nuclear monitoring organization, to Iran this month came away with less than it hoped for.

Iran allowed the team to visit part of a huge military facility, called Parchin. The Bush administration has long suspected that testing of high explosives in one area of the site could be part of a program to develop a nuclear warhead. Iran insists that all of its nuclear work is for civilian purposes.

Iran was under no international treaty obligation to allow the inspection and it stopped inspectors from visiting a bunker for high- explosive testing of conventional weapons.

In the interview today, Dr. ElBaradei confirmed that the International Atomic Energy Agency had asked for a return visit. "We´re looking at testing grounds, yes," he said, adding, "We try to go everywhere we think there might have been possible use of nuclear material that has not been declared to us."

Meanwhile, the Europeans cannot deliver on some of the more ambitious rewards they are discussing with Iran under their accord because they depend on American approval.

In conversations with Ms. Rice and other administration officials since Mr. Bush´s re-election, for example, the Europeans have tried but failed to persuade them to accept Iran´s application to open membership talks with the World Trade Organization.

All of Iran´s European negotiating partners have argued that one of the best ways to promote democracy would be to force more transparency into Iran´s economy. That could help break the stranglehold of the vast system of government- protected "foundations," most of them the private fiefs of powerful clerics, European officials said.

"You cannot just ask Iran to renounce its nuclear program," said Mr. Barnier. "You have to allow it to be a positive actor, to enter in this constructive logic of stability. It´s a ´win-win´ deal that we have proposed." (Copyright 2005 The New York Times Company 01/29/05)