The Bush administration confirmed Wednesday it has granted Iranian President Mahmoud Ahmadinejad a visa to attend next week's United Nations summit in New York. But officials say questions about his possible role in the 1979 seizure of the U.S. embassy in Tehran remain.

The United States is obligated under the 1947 United Nations headquarters agreement to facilitate travel by world leaders to U.N. events in New York.

Officials here say the Bush administration is doing so in the case of Mr. Ahmadinejad, even though he was found to be technically ineligible for a visa under U.S. law.

The Iranian President, a political hard-liner elected to office in June, applied for a U.S. visa a month ago to attend next week's global summit marking the United Nations' 60th anniversary.

The Bush administration had already been examining Mr. Ahmadinejad's past, amid charges from former hostages that he had a personal role in the 1979 seizure of the U.S. embassy in Tehran and the holding of 52 American hostages for 444 days.

At a news briefing, State Department Spokesman Sean McCormack said Mr. Ahmadinejad's precise role in the embassy siege remains unclear, in part because the Iranian government has yet to answer U.S. questions about the matter.

Mr. McCormack said Secretary of State Condoleezza Rice directed that Mr. Ahmadinejad be given the visa, even though an inter-agency review found him to be ineligible under immigration rules barring visas to those for whom there are reasons to believe have supported or furthered acts of terrorism:

"We did find Mr. Ahmadinejad ineligible," Mr. McCormack says. "We then requested a waiver of that ineligibility finding, and a visa was issued. There are still unresolved questions concerning his activities surrounding the taking of the American embassy in Tehran, and his activities in that subsequent period in which Americans citizens  were held for 444 days. We have not forgotten that, and we call upon the Iranian government to clarify and to answer these questions that have yet to be answered."

Iran has said Mr. Ahmadinejad was a student leader during the country's Islamic revolution, but did not have a direct hand in the embassy seizure. Several former hostages however said they recall him taking part in interrogations of the prisoners after the takeover.

Spokesman McCormack noted that in keeping with its U.N. obligations, the United States has never denied a visa to a head of state or government attending U.N. functions.

He said Mr. Ahmadinejad, like other members of Iran's U.N. delegation, will be barred from traveling more than 25 miles outside New York during his U.S. stay.

Mr. McCormack said the decision to grant the visa in no way indicates a change in the United States' policy, or views, toward the Iranian government.

Mr. Ahmadinejad could attend U.N. events in which President Bush and Secretary Rice may also participate, though a senior official here said he expected no inter-action between them.

Despite the lack of diplomatic relations, U.S. and Iranian officials have met occasionally in recent years to discuss issues of mutual interest.

Iran's state radio said Tuesday that the Tehran government was prepared to supply the United States with 20 million barrels of crude oil to help deal with the devastation from Hurricane Katrina, provided it lifted sanctions against Iran.

Bush administration officials, though accepting in principle all offers of foreign assistance, Wednesday brushed aside the Iranian gesture because it was conditional.

Iran allowed an airlift of U.S. relief supplies after the 2003 earthquake in the city of Bam.

There have also been limited cultural exchanges but the relationship remains chilly, amid U.S. charges that Iran supports Middle East terrorism and is seeking nuclear weapons.