COMBAT IN PANAMA : Washington Keeping Moscow Fully Informed About Invasion : Foreign Policy: U.S. officials hope candor will help climate of warmer relations.

American diplomats, hoping to foster a climate of warmer relations between Washington and Moscow, began keeping Soviet officials closely advised of the course of events in Panama days before the incursion and continue to brief Kremlin officials several times daily, U.S. sources in Moscow said Friday.

The degree of communication between Soviet and American officials has occurred at all levels and took place with increasing detail and intensity at least two days before the American intervention into Panama, reflecting deep concern in Washington that nothing upset the new style of cooperation between the two countries.

And, for the most part, keeping the Soviets closely advised is a tactic that has worked, according to American officials here.

Despite the tough rhetoric coming from the Kremlin, Soviet officials have made it clear that U.S.-Soviet relations will not be damaged because of the military intervention, the American diplomats say.

Dozens of Soviet citizens Friday expressed their anger over the events in Panama, demonstrating in front of the U.S. Embassy. Some carried signs that read “Hands Off Panama.”

For the third day in a row, the official Tass news agency made highly critical comments on the U.S. actions, saying: “American-style democracy is being imposed on Panama by army helicopters, tanks and armored carriers. . . . The White House has found itself isolated again.”

But stern statements by the government and in the official media, according to one senior U.S. official, are simply “a matter of image.”

“I don’t think they are all that upset. But they don’t want to be seen as being in collusion with us,” the official said.

That is particularly important for President Mikhail S. Gorbachev, who reportedly has been accused by conservatives of putting good relations with the West before ideological concerns.

Georgy A. Arbatov, a key Kremlin adviser on East-West relations, called the American incursion “the best Christmas present the Americans could have given the Soviet military machine.”

It would strengthen the hand of those in Soviet military and political circles who argue that the Soviet Union should not move so quickly to make unilateral disarmament agreements, he told reporters during a break in the current session of the Congress of Peoples’ Deputies.

An attempt to deflect potential criticism from conservatives may be a key factor behind the tough wording of the official Soviet response to Panama, officials said.

“We were a bit surprised by the tone and degree of their public criticism,” one American political analyst said of the initial Soviet response to Panama. “It was more aggressive than we might have expected.

“But, based on our private conversations, we see no long-term, substantive problems between Washington and Moscow because of this,” the analyst said in an interview.

A flurry of meetings “at a number of levels” were held in Moscow on Tuesday, before American troops intervened in Panama, one American diplomat said. While the Soviets were not provided with exact details of the American plans, “the news that we had sent in troops came as no surprise to them,” the diplomat added.

“We took the initiative to go in and provide an explanation,” another senior official explained. “We didn’t give them advance word about the operation itself, but we expressed our concern about the way things were developing.”

Soviet officials have refused to discuss their contacts with their American counterparts before the American intervention into Panama.

Foreign Ministry spokesman Vadim P. Perfiliev, speaking at a news conference this week, declined to confirm or deny if there had been any contacts between American and Soviet officials before the invasion.

“I am not authorized to comment on this matter,” he said.

The official media has reported that Gen. Manuel A. Noriega is targeted by the United States because of his nationalist views and has described the drug charges leveled against him as unfounded.

But in private meetings with American officials, “the Soviets said they recognized Noriega was not a wonderful character,” one U.S. source in the Soviet capital said. “They didn’t say they thought it was right for us to send in troops, but their criticism in private was more mild than it was in public.”

While the Soviet Union does not share close relations with Panama and neither country has an embassy in the other’s capital, Moscow’s Communist ally Cuban President Fidel Castro is a staunch supporter of Noriega.

“In the light of the Cuban position, Moscow could clearly not stand by and say nothing about Panama,” one Western diplomatic analyst said.

But, regarding the long-term effect on Soviet-American relations, the analyst said: “I see absolutely nothing that would suggest to me that they wish to carry this into other areas--quite to the contrary, all other appointments are going on normally.”

And a longtime Soviet analyst agreed. “It is, without doubt, an irritant in the public arena,” he said. “But it will not affect the course of Soviet-American relations.”