The Soviet military chief of staff said at the beginning of an unprecedented tour of U.S. military bases that he didn't see any similarity between the downing of an Iranian airliner last weekend and that of a Korean airliner by Soviet forces in 1983.

Marshal Sergei F. Akhromeyev said he discussed the incident with his U.S. counterpart and host, Adm. William Crowe, but had refrained from giving advice."Yesterday, Adm. Crowe informed me about that, and he told me about the specifics, and we took some time discussing this," said Akhromeyev, speaking in Russian. "I and Adm. Crowe are military professionals, and I did not see fit to offer any military advice.

"I would not draw any similarities between the Iranian airliner a few days ago and the downing of a Korean airliner a few years ago," Akhromeyev told a Pentagon news conference.

Pressed to explain the differences between the two incidents, Akhromeyev smiled and said, "I believe you would be more interested in the subjects we are discussing today" as part of the continuing dialogue between U.S. and Soviet armed forces.

Crowe and others in the briefing room laughed as Akhromeyev ducked the question, and the American admiral said a few minutes later that he was "looking forward to facing the Soviet press" when he accepts the Soviet marshal's invitation to visit Moscow at a later date.

Crowe, at a grim news conference Sunday announcing that an U.S. warship had shot down Iran Air flight 655 with 290 people aboard, said there were "fundamental differences" between it and the downing of Korean Air Lines flight 007 on Sept. 1, 1983.

The key distinction, said Crowe, was that the Americans fired on the Iranian jetliner in an area of combat, while the Soviets shot down KAL 007 in an area free of hostilities.

"The fundamental differences, of course, are that it was not a war zone," Crowe said of the KAL incident. "There was not combat in prog-ress. There was not combat there normally" over the Soviet Kamchatka Penninsula, where KAL 007 was shot down by Soviet fighters.