An intelligence report indicating an Iranian official had said his country had enough nuclear materials to build a bomb has led agency analysts recently to hedge their bets about whether Tehran can produce such a weapon, according to administration sources.

A spokesman for the CIA would only say yesterday that the agency has had a "long interest" in Iran's nuclear weapons research and has been "watching it on a continuing basis." Asked about a change in the agency's assessment, he responded, "There are as many opinions as analysts on that subject." The CIA's new view of Iran's nuclear potential was reported in Monday editions of the New York Times.

A senior administration official who follows nuclear weapons activities said yesterday that when the CIA report on the Iranian's remark first circulated last year, "it was not viewed as very significant." It is only recently that the agency has "made it an asterisk" in their analysis, he added.

"We don't want to discount the possibility," he said, "but no one is asserting they [the Iranians] have enough for a bomb."

Iran has made no secret that it has had a nuclear weapons program for more than 15 years, driven primarily by Iraq's program and Baghdad's use of chemical weapons during their war. Another incentive was Israel's possession of nuclear weapons.

Even though Iran ratified the Nuclear Nonproliferation Treaty in 1970 and since 1992 has allowed inspectors from the International Atomic Energy Agency (IAEA) to look at its nuclear facilities, it has repeatedly tried to overcome the major weakness in its program--the lack of either enriched uranium or plutonium, the key nuclear materials needed for a bomb. Since the early 1990s, Iran has been purchasing equipment that could be used in a peaceful or nuclear weapons program from Russia, China and European countries.

Russia is helping complete construction of Iran's primary nuclear reactor at Bushehr and Moscow is training Iranian nuclear scientists. The Russians have publicly insisted that Iran abide by IAEA rules. Meanwhile, China is aiding in four other of Iran's nuclear facilities.

In 1992 and in 1995, U.S. intelligence analysts said that Iran could achieve a nuclear capability by 2000. In a 1997 analysis, the Pentagon reported that Iran was still trying to acquire enough nuclear material for its weapons program "and has set up an elaborate system of military and civilian organizations to support its effort."

In 1992, there were inaccurate reports that Iran had bought nuclear weapons from Kazakhstan. U.S. intelligence is also aware of several failed efforts by Iran to purchase nuclear materials from Russian traders, and at least twice Iranians have been caught in stings while attempting to acquire weapons grade materials, according to administration officials.