UNITED NATIONS — Days before Iran’s president arrives here for the annual U.N. General Assembly session, his country is ratcheting up its defiance of America and the International Atomic Energy Agency.

The IAEA is taking Iran to task over its refusal to cooperate with nuclear inspectors and its violation of U.N. Security Council resolutions, but far from being ostracized at the General Assembly, President Ahmadinejad is expected to be fêted by some of the key countries attending the session.

IAEA officials told reporters yesterday that they have arrived at an impasse in their efforts to verify Iran’s contention that its nuclear program is designed solely for peaceful purposes. Iran responded by heightening its anti-Western rhetoric and conducting air exercises aimed at countering a possible attack on its nuclear installations.

Leading members of the Security Council are considering imposing new punitive measures against Iran this month, American officials said yesterday, though in order to reach agreement the measures would likely need to be softened. The political directors of the five permanent members of the council and of Germany are expected to meet Thursday, and the foreign ministers of the group will meet next week on the sidelines of the General Assembly debate.

But as they deliberate over how best to respond to the IAEA’s latest report, issued yesterday, Western leaders will have to consider the alliances of Mr. Ahmadinejad, who is expected to address the world body next Tuesday and receive a salutary toast later that week from the General Assembly’s highest elected official, Miguel d’Escoto Brockmann of Nicaragua, its new president.

“It’s imperative that they cooperate” or “face the prospect of further sanctions,” the American ambassador to the United Nations, Zalmay Khalilzad, said of the IAEA report. But he acknowledged that the increasingly divided Security Council could have additional problems uniting because of Russia’s recent conflict with Georgia. Russia has been Iran’s staunchest defender in past council deliberations.

“Certainly Georgia is there, and I don’t want to understate that it’s there,” Mr. Khalilzad told The New York Sun. “At the same time, Iran’s moving forward to acquire nuclear weapons capabilities is an issue that the Russians have indicated is of concern to them, and certainly it’s of concern to us.”

Despite the IAEA report, Mr. Ahmadinejad is expected to be celebrated by some admirers when he arrives in New York for the General Assembly. Mr. d’Escoto, who assumed the one-year assembly presidency yesterday, will address an Iranian-sponsored gathering of “political religious leaders” on September 26 at Manhattan’s Grand Hyatt Hotel, at which the Iranian president will be the guest of honor, according to an invitation for the event.

Yesterday’s report took Iran to task on several outstanding inspection issues, including its experimentation with detonators for nuclear weapons. Iran has denied conducting “experimentation in connection with symmetrical initiation of a hemispherical high explosive charge suitable for an implosion type nuclear device,” the agency’s outgoing director, Mohamed ElBaradei, writes in the six-page periodical report. But agency inspectors have obtained information that shows that such experiments did take place and, further, that they “may have involved the assistance of foreign expertise,” Mr. ElBaradei writes.

Sources in Vienna, where the IAEA is based, declined to identify the foreign experts. Iran has not cooperated in clarifying the issue and several other questions, Mr. ElBaradei writes. “Contrary to the decisions of the Security Council, Iran has not suspended its enrichment-related activities,” he adds.

Iran’s foreign minister, Manouchehr Mottaki, requested a meeting yesterday with his German counterpart, Frank-Walter Steinmeier. As a top European power that maintains commercial ties with Iran, Germany was added to the five permanent Security Council members — America, Britain, France, China, and Russia — as part of the group steering policy on Iran. Some diplomats consider Germany to be the “weakest European link” in the group, but after an hourlong meeting in Berlin yesterday with Mr. Mottaki, Mr. Steinmeier said he was disappointed with Iran’s lack of cooperation.

“Our cooperation with the agency … especially during the last year, has been sincere, serious, and in the framework of the agency’s responsibilities,” Mr. Mottaki said Sunday in Tehran, according to Iran’s Fars news agency.

Separately, the Iranian air force yesterday conducted exercises to prepare the country for a possible Israeli or American attack against its nuclear installations, Fars reported.

“If Iran is attacked, it will deliver a crushing blow to the enemy,” an Iranian air force commander, General Ahmad Miqani, told Fars. “We will surprise the enemy and make them regret they attacked.”