Iran's hard-line president told his nation Monday not to be frightened by Western "bullying" over the country's nuclear ambitions, and his government dismissed as "psychological warfare" reports that the United States was drawing up plans for military action.

In Washington, President Bush said force is not necessarily required to stop Iran from having a nuclear weapon, and he dismissed reports of plans for a military attack as "wild speculation."

The comments by Iranian President Mahmoud Ahmadinejad and Bush came after several American media reports said the Bush administration was studying options for military strikes against Iran to stop its nuclear program.

An account in The New Yorker magazine said U.S. officials were looking at the possibility of using nuclear bombs against Iran's underground nuclear sites.

Ahmadinejad said Iran would not be dissuaded from its nuclear goals. Tehran insists its nuclear program aims to develop energy, denying U.S. and Western accusations it intends to build nuclear weapons.

"Our enemies know that they can't cause a minute's pause in our nation's motion forward," Ahmadinejad told thousands of people gathered in Mashad, capital of Razavi Khorasan province in northeastern Iran.

"Unfortunately, today some bullying powers are unable to give up their bullying nature. The future will prove that our path was a right way."

"They have pinned their hope to create differences among our nation," Ahmadinejad said. "There are some weak people who intend to frighten our nation. I do advise people not to be afraid when some international power frowns."

It was not clear if Ahmadinejad's speech was referring to the reports of U.S. military planning and of operatives stirring dissent in Iran's ethnic minorities. His comments also came after European Union foreign policy chief Javier Solana recommended Monday that the 25-nation bloc consider sanctions against Iran, including a visa ban on some officials, because of Iran's rejection of U.N. demands it end uranium enrichment.

Iranian Foreign Ministry spokesman Hamid Reza Asefi dismissed the reports of U.S. military planning.

"We see it as psychological warfare, resulting from the Americans' anger and despair" over stopping Iran's nuclear ambitions, he told journalists when asked Sunday about the reports.

Ali Larijani, the secretary of Iran's supreme National Security Council, also played down the reports.

"If the U.S. commits such a mistake, it would receive a convenient answer," Larijani said, according to a Monday report by the state news agency IRNA.

Bush said his goal is to keep the Iranians from having the capability or the knowledge to have a nuclear weapon.

"I know we're here in Washington (where) prevention means force," Bush said during an appearance at the Paul H. Nitze School of Advanced International Studies at Johns Hopkins University. "It doesn't mean force necessarily. In this case it means diplomacy."

British Foreign Secretary Jack Straw, in an interview with the British Broadcasting Corp. on Sunday, called the idea of a nuclear strike on Iran "completely nuts."

The U.N. Security Council has demanded that Iran suspend all enrichment of uranium — a key process that can produce either fuel for a reactor or the material for a nuclear warhead — and gave Tehran until April 28 to comply before the International Atomic Energy Agency reports back to the council on its inspection progress.

Iran has rejected the demand, saying the small-scale enrichment it began in February was strictly for research and was within its rights under the Nuclear Nonproliferation Treaty.

On Sunday, five IAEA inspectors visited Iran's Uranium Conversion Facility in Isfahan that reprocesses raw uranium into hexafluoride gas, the feedstock for enrichment.

The team was next due to visit theNatanz uranium enrichment plant, where Iran resumed small-scale research enrichment in February. The inspectors, who arrived in Tehran on Friday, will stay in Iran for five days.