The Bush administration yesterday praised the selection of Soviet Ambassador Alexander Bessmertnykh as the new Soviet foreign minister, but U.S. officials said it remains highly uncertain whether he will be able to maintain the cooperative relationship that has developed between Moscow and Washington in recent months.

Whether there is continuity or severe backsliding in U.S.-Soviet relations depends less on the quality of diplomacy from the Soviet Foreign Ministry than on the direction of the Soviet Union's domestic policy, which may become apparent first in the streets of Vilnius, Lithuania, and the other Baltic capitals in days to come, U.S. officials said.

Because of the crisis in the Baltic republics, "we have a day-to-day perspective on the state of relations" with the Soviet Union, said a senior administration official who is closely following the situation. The Baltic situation is "not very encouraging," this official said, especially because Soviet President Mikhail Gorbachev did not condemn last weekend's violent crackdown in Lithuania or say it would not happen again.

The naming of Bessmertnykh, who was the personal choice and, to an unusual extent, the personal envoy of Gorbachev as Soviet ambassador to Washington since last May, was hailed by the administration. White House press secretary Marlin Fitzwater said, "We know him well, respect him; we can work with him." Similar words of praise came from State Department spokesman Margaret Tutwiler, who called Bessmertnykh "a skilled diplomat of long standing."

After praising the new minister, however, Tutwiler said "the events of the last few days in the Baltics deeply disturb and concern us." She added that a crackdown by Moscow threatens "to set back or even reverse the process of reform" in the Soviet Union and that "there can be no lasting U.S.-Soviet cooperation without shared values" flowing from these reforms.

Secretary of State James A. Baker III met with his top aides for a full-scale discussion of Soviet policy in the light of the crackdown and asked officials to draw up options for further U.S. responses if it continues, State Department sources said. Later, Baker called in the acting Soviet ambassador, Sergei Chetverikov, to reiterate that "the United States sees absolutely no justification for the use of force against the peaceful and democratically elected government of Lithuania," the State Department said.

Administration officials said it seemed likely that there will be more major developments in the Baltic states within the next few days, possibly either a pullback to ease the situation or a more vigorous suppression of popularly elected Baltic governments.

Several official and nongovernment experts on Soviet affairs said the selection of Bessmertnykh is a welcome sign that Gorbachev is emphasizing continuity in foreign policy and intends, if possible, to keep his relations with the United States and the West generally on an even keel. By picking a career diplomat with extensive experience in Washington and the West rather than a political figure, "it means that Gorbachev will be his own foreign minister," said William Hyland, editor of Foreign Affairs magazine and a former U.S. government official.

Bessmertnykh served as a senior deputy to former foreign minister Eduard Shevardnadze before being posted to Washington last spring and was considered close to Shevardnadze in policy terms as well as personally. The new foreign minister began his first speech to the Supreme Soviet legislature yesterday with extensive praise of Shevardnadze.

An administration official made the point, however, that Bessmertnykh does not have "the kind of inner-circle relationship Shevardnadze enjoyed" as a longtime personal friend of Gorbachev and a senior figure in the Communist Party before becoming foreign minister. Hyland said Gorbachev may not have wanted "any Shevardnadze type of incidents," referring to occasional disagreements between the two men and Shevardnadze's dramatic resignation last month over what he called the threat of "dictatorship."

There was a broad consensus among a half-dozen Soviet experts, in and out of government, that the future course of the Soviet Union and of U.S.-Soviet relations is at an unusually important moment right now, with Soviet military forces poised to take further strong actions in the Baltics and the balance of political power as well as Gorbachev's position in Moscow in a highly uncertain state.

Last weekend's events in Lithuania were "a great tragedy . . . but we don't know exactly what they mean," said Prof. Stephen Cohen of Princeton University, who recently returned from Moscow. "We don't know whether Gorbachev will use the fist, or be forced to it, and whether he will survive."

Arnold Hoerlick of Rand Corporation, a Soviet scholar and former CIA official who recently visited Moscow, said the current "critical stage" might be decisive for the domestic trends in the Soviet Union. While it is "not a time to burn all bridges," said Hoerlick, he said the Bush administration's public position "should have been much tougher" regarding the developments in Lithuania.