DEFENSE Secretary William Perry may have received the brushoff this week when he tried to persuade Russia to cancel a nuclear-reactor sale to Iran. But United States officials continue to work behind scenes to halt the deal -- and they hope to change Moscow's mind by the May 9 meeting between President Clinton and his Russian counterpart, Boris Yeltsin.
Washington, for instance, may be willing to cut Russia in on a $4 billion international project to supply reactors to North Korea, if it forgoes Iran's cash.
''What we're looking for is a public commitment that the Russians will basically do what we feel is the right thing on the reactors,'' one US official says.
Moscow's plan to sell up to five nuclear reactors to Iran is emerging as perhaps the most nettlesome issue in current US-Russian relations. To Russia, the deal represents prestige, plus desperately needed cash and employment in high-tech industries. To Washington, it would mean a setback for nuclear nonproliferation efforts -- plus a slap at the US policy of isolating Iran.
The deal threatens to sour the May summit and its celebration of the 50th anniversary of the Allies' triumph over Nazi Germany.
While expressing hope for a resolution in time for President Clinton's visit to Moscow, some US officials caution that the reactor dispute may be too complex to iron out before the trip.
''It's not realistic to assume that we are going to resolve the problem before the summit,'' says one US official, speaking on condition of anonimity. ''Our view is that you have summits to discuss real problems, and this is a real problem. We are moving fast on this and hard on this.''
Although the reactors would ostensibly be used for electricity generation and research, Washington says they could help the Islamic republic of Iran develop the technological skills it needs for an alleged nuclear-weapons development program.
The US has long accused Iran of promoting terrorism, trying to undermine the Middle East peace process, and developing biological, chemical, and nuclear arms. The administration's so-called ''containment'' policy has tried to isolate the Iranian leadership by discouraging other states from trading with it.
The White House is examining steps to shore up domestic compliance with its policy, and an internal administration debate is now under way on whether to ban US companies from all trade with Iran. The measure would be aimed at American oil firms that buy Iranian petroleum and sell it on the world market.
Some US officials oppose such a ban because it would hurt US companies. But others say it is needed to demonstrate US intentions to deal resolutely with Iran. ''There is a good deal of studying going on,'' says one official.
Russia's latest refusal to halt its reactor deal with Iran came in an April 3 meeting in Moscow between Russian Prime Minister Viktor Chernomyrdin and Mr. Perry, who is on a week-long tour of parts of the former Soviet Union. In his talks with Mr. Chernomyrdin, Perry reiterated the US contention that it is in Russia's own interest to stop one of its neighbors from acquiring nuclear-weapons capabilities.
But Perry also acknowledged that the huge profits the cash-strapped Russian government would earn from the reactor sale makes it ''very hard'' for it to cancel the deal. Some US officials, however, contend that Iran's economic woes are so deep that it will never be able to pay Russia for the reactors.
The next round in the dispute will commence when deputy secretary of state Strobe Talbott travels to Moscow this week for pre-summit talks that are expected to include a meeting of a new US-Russian working group on arms proliferation issues.
It will be in this forum that US officials will step up the pressure on the Russians to cancel the reactor sale, officials say. One official confirmed that Washington has ''shared a degree'' of intelligence information with the Russians on Iran's alleged secret nuclear-weapons program as part of its lobbying effort.
In Washington on April 4, State Department spokeswoman Christine Shelly denied that Russia had been promised a share of the project to replace North Korea's existing nuclear reactors with more proliferation-resistant models. But she clearly left open the door for Russian participation, saying that ''portions of this contract'' could be subcontracted to other nations.
Last January, Russia and Iran signed a $1 billion accord under which Moscow is to complete the construction of one of two nuclear power reactors -- known as Bushehr 1 and 2 -- that the German company, Seimens, began building in 1976 on Iran's Persian Gulf coast. The projects were suspended after the 1979 overthrow of the late Shah of Iran.
A second accord is believed to be ready for signing that calls for Russia to finish the second Bushehr reactor. In addition, Iran is reportedly interested in purchasing two smaller Russian power reactors and a research reactor. The Russians argue that the reactor deals are legal as Iran is a signatory of the Nuclear Non-Proliferation Treaty (NPT), which allows transfers of peaceful nuclear technologies. They also compare their deal with Iran to the US agreement to help provide North Korea with power reactors.
But US officials dispute the Russian contentions, saying that Iran is violating the NPT by secretly developing nuclear weapons. And they say that North Korea has halted its nuclear-arms development program in return for the power reactors.