The Iranian government is buying $2 billion worth of weapons from foreign suppliers each year in a drive to again become the preeminent power in the Persian Gulf region, CIA Director Robert M. Gates said yesterday.

Russia, China and North Korea have been the principal sellers of armaments to Iran, although Tehran is attempting to buy hundreds of tanks from eastern European suppliers, Gates told the House Armed Services Committee.

Iran's burgeoning, foreign-made arsenal includes advanced warplanes, antiaircraft missiles and some extended-range Scud missiles, said Gates, adding that the country has also contracted to buy at least two Russian submarines.

Gates's testimony provided new details to earlier U.S. descriptions of the Iranian rearmament effort, estimating that the total cost of foreign-made weapons acquired by Iran between 1990 and 1994 will reach $10 billion. That is a substantial sum for the country, particularly in light of its struggle to repair the damage done by the 1980-88 war with Iraq.

"It is a real drain on their economy," a government analyst said later. "There will be a lot of belt-tightening to make it possible."

Although Gates also took note of recent signs that Iran is moderating its behavior toward neighbors, he presented a highly pessimistic view of the country's long-term goals in a brief, prepared statement before the House committee closed its doors for a classified session. Calling Iran one of several nations in the Middle East that are "hostile to U.S. interests," Gates said "its clerical leadership has not abandoned the goal of one day leading the Islamic world and reversing the global dominance of Western culture and technology."

U.S. and Russian officials have expressed concern about the potential spread of Iran's revolutionary brand of Islamic ideology to the new Asian nations created by the breakup of the Soviet Union. But Gates said that while Iran has begun forging diplomatic and other ties with these nations, the United States has "no evidence of Iranian efforts to subvert the secular governments" of the former Soviet republics. "For now, at least, Iran seems to want to preserve amicable relations with Russia, which has become a major source of its arms," he said.

As one recent sign of Tehran's moderation, Gates cited an Iranian effort to restrain Azerbaijan in its conflict with Armenia. He said that within the Middle East, Iranian President Ali Akbar Hashemi Rafsanjani "is trying to cultivate an . . . image of responsibility and respectability" aimed at fostering foreign investment and appealing to those Islamic countries with which Iran wants to improve ties.

But Gates also said that "Iran's growing support of radical Palestinian groups may bring it closer to some Arab states such as Libya" and added that the U.S. intelligence community expects "Iran to continue to strongly oppose the {Middle East} peace process, and probably to promote terrorism and other active measures aimed at undermining progress toward Israeli-Palestinian reconciliation."

Gates reiterated an earlier CIA claim that Iran is trying to acquire a nuclear weapons capability, but added that this goal is unlikely to be achieved before the year 2000. Another Iranian weapons effort -- the development of poison gas warheads to place atop Scud missiles -- is likely to succeed sooner, Gates indicated, saying the country's "relatively crude" chemical weapons program is expected to produce such warheads within a few years. "We also suspect that Iran is working toward a biological warfare capability," he said.

"Tehran is rebuilding its military strength not only to redress the military imbalance with Iraq," said the CIA director, "but also to increase its ability to influence and intimidate its gulf neighbors."

Speaking also about Iraq yesterday, Gates said that the regime of President Saddam Hussein retains some mobile Scud missile launchers and as many as several hundred missiles. He said the CIA suspects that, despite the continued efforts of United Nations inspection teams, some of Iraq's nuclear weapons-related equipment remains hidden. So do some chemical and biological weapons and the means to make more, Gates added.

He said that if U.N. sanctions were removed, Iraq could restore its conventional military arsenals to their pre-Persian Gulf War levels in three to five years. "Long before then, Iraq's forces could be strong enough to threaten its neighbors," the CIA director said.