U.S. officials yesterday were reluctant to express publicly more than cautious concern about reports of Soviet troop movements into the Baltic republics, saying there was insufficient information available here about Moscow's intentions.

"We are seriously concerned about the possibilities for violence and forceful suppression of the Baltic people's right to self-determination, and if that happens, we would have no choice except to speak out forcefully on their behalf," said a senior State Department official who asked not to be identified. "But we also want to know exactly what is going on before we stick ourselves in the middle."

His remarks were echoed by other officials fearful that the development of cordial, cooperative relations between Soviet President Mikhail Gorbachev and President Bush could fall victim to new repressive measures the Soviet leader may feel compelled to take.

The uncertainties of the internal Soviet situation -- along with the looming possibility of a U.S.-led war against Iraq and difficulties in achieving U.S.-Soviet agreements on arms control -- have stirred speculation that Bush might postpone the planned summit with Gorbachev in Moscow on Feb. 11-13.

"I guess it's fair to say that there's always the possibility that the trip could be delayed, but at this point we still intend to go," White House spokesman Marlin Fitzwater said in response to questions on a possible postponement reported by Cable News Network and some Monday editions of the New York Times.

Gorbachev has been beset by conflicting domestic pressures. On the one hand are conservatives demanding a return to communist orthodoxy. On the other are reformers fearful of a swing back toward dictatorship. He also confronts separatist tendencies in the Baltics and other parts of the country that could cause the breakup of the vast Soviet empire.

Some American officials fear that a strong, public U.S. stance backing independence for Lithuania, Latvia and Estonia could strengthen conservatives wanting to crack down on separatism, thereby undermining Gorbachev's ability to retain power. At the very least, many officials acknowledge, there is likely to be be a dramatic cooling in U.S.-Soviet relations that would adversely affect progress toward arms control, establishment of a peaceful new order in Europe and maintenance of the international coalition confronting Iraq in the Persian Gulf.

However, the officials stressed, while the United States would be very distressed by such a setback in relations, the U.S. commitment to self-determination throughout Europe and the resolution of internal Soviet conflicts through peaceful means would leave Washington no choice but to denounce a Soviet military crackdown in unequivocal terms. The hope here, the officials added, is that the looming crisis will cool off before it reaches that point.

For that reason, the administration responded cautiously to yesterday's reports that the Soviet defense ministry is sending several divisions of paratroopers into troubled regions of the Baltics, the Ukraine and the Caucusus, saying it had insufficient information to assess the situation properly. It also limited public comment by Fitzwater and State Department spokesman Richard Boucher to identical restatements of the policy followed by Washington since the separatist problem became serious last year.

The spokesmen reiterated "the United States has never recognized the forcible incorporation of the Baltic states into the Soviet Union, and we support the aspirations of the Baltic peoples to control and determine their own future." They said the U.S. ambassador in Moscow, Jack Matlock, who visited the Soviet foreign ministry yesterday on another matter, "pointed out that the leaders and people of the Baltic states have conducted themselves with dignity and discipline, and he reiterated the U.S. policy on behalf of peaceful negotiations."