President Bush said yesterday that the United States is likely to grant a visa to Iran's new president for the United Nations' opening session next month, even though the administration continues to probe whether Mahmoud Ahmadinejad was connected to the 1979-1981 seizure of the U.S. Embassy in Tehran.

The tentative decision comes as a secret U.S. intelligence report circulated within the administration yesterday said that there is so far no evidence Ahmadinejad was involved -- and that he may have opposed the takeover because of fears about the neighboring Soviet Union -- according to U.S. officials familiar with the report.

Many devout Muslims feared the former communist state, both because of its atheist ideology and because of its occupation of northern Iran during and after World War II, which sparked the first crisis at the United Nations. In a speech more than six years ago, Ahmadinejad publicly challenged the wisdom of the takeover, the report notes.

"There is relative certainty that he was not one of the actual captors," said a U.S. official familiar with the allegations, first made by at least four former hostages based on the similarity between pictures of Ahmadinejad and a bearded young captor.

All week, the State Department has been interviewing some of the 52 people held in Iran for 444 days to see whether they can provide specifics that would alter their initial assessment, State Department officials said.

The U.S. intelligence community now believes it was a case of mistaken identity. The original embassy captors also denied that Ahmadinejad played a leadership role or that they knew him at the time, even though he was a student activist during that period.

The secret report also says U.S. intelligence has found no evidence to back up assertions from Iranian dissidents that Ahmadinejad was involved in planning the assassinations of Iranian Kurdish politician Abdul-Rahman Ghassemlou and two colleagues on July 13, 1989, in Vienna. The report says there is ambiguity about the president's possible knowledge of the death of another dissident in Tehran's Evin prison, U.S. officials say.

The intelligence report is not considered final or conclusive, stressed officials, who would discuss it only on the condition of anonymity because it is classified. But it lays out all available evidence as well as the sources of claims about misadventures by Iran's president; some of the sources have their own agendas or biases, the report notes, according to U.S. officials.

"It wants to leave people as much room for debate, discussion as possible," said a senior State Department official. "Therefore, characterizing it or providing information about what we think, or believe, or where we are either prejudges or constrains discussions and decision-making. We're in the middle of this. It's not the end of the game by any means."

For now, the administration appears willing to let the Iranian president make his first trip to New York -- which would also be his first trip to the West. "We have an agreement with the United Nations to allow people to come to meet, and I suspect he will be there to meet at the United Nations," Bush told reporters at his Texas ranch. He noted the investigation of the allegations. His comments came as the United States and European allies tried to persuade Iran to resume a suspension of its nuclear program and to return to talks aimed at ensuring it does not build atomic weapons.

Ahmadinejad has had limited exposure to the outside world. At the United Nations, Secretary General Kofi Annan said he will use the mid-September U.N. opening -- expected to be attended by more than 170 world leaders -- to bring Iran's new leader into contact with his Western critics. "We will use the General Assembly to bring them together," he told Reuters.