The Bush administration sharply criticized the Soviet Union yesterday for attempting to intimidate the Baltic states through military means, as U.S. concern grew that Soviet internal developments could derail the new era of Soviet-American cooperation.

In a notable hardening of U.S. rhetoric, White House press secretary Marlin Fitzwater called the Soviet decision to send troops to the Baltics to enforce the military draft "provocative and counterproductive." He urged the Kremlin "to cease attempts at intimidation and turn back to negotiations" in dealing with the rebellious republics.

Fitzwater also criticized the decision to send Soviet troops to four republics outside the Baltics, although in more restrained language. Unlike the other republics, the Baltics are considered a special case for U.S. policy because the United States has never recognized their forced incorporation into the Soviet Union.

Administration officials said the Fitzwater statement arose from concern that an internal crisis in the Soviet Union, especially a military crackdown in the Baltics, could jeopardize U.S.-Soviet relations at a time when cooperation with Moscow is especially important in the Persian Gulf. One official characterized the statement as laying down a marker to the Soviet Union about the U.S. national interest in averting a crisis.

In a similar situation last spring, the White House issued strong statements about Moscow's economic embargo against Lithuania, one of the three Baltic states along with Estonia and Latvia. On April 24, however, President Bush said he had decided not to order any U.S. sanctions against the Soviet Union because of the high U.S. stakes in existing Soviet foreign policy, at that time especially the Soviet attitude toward the future of a unified Germany.

The stakes are equally high in the present situation, according to administration officials, but in some respects there is even greater concern now in Washington about Moscow's domestic policies. The decision to send additional troops to rebellious republics, ostensibly to enforce the often disregarded conscription laws, was seen by these officials as only the latest of a cumulative series of moves suggesting that President Mikhail Gorbachev is turning toward the use of military and police powers rather than political persuasion.

White House and State Department officials denied a New York Times report that the White House has instructed State to explore a suitable way of postponing the U.S.-Soviet summit meeting, now scheduled for Feb. 11-13 in Moscow. Fitzwater said it would be "premature" to suggest any change in U.S. plans for the meeting on the basis of what has happened.

Officials conceded, however, that the summit could be postponed, especially if a war in the Persian Gulf makes it unwise for Bush to leave the country at that time, or if the strategic arms treaty, the signing of which is the principal rationale for the summit meeting, is not ready. U.S. negotiators have reported problems in resolving final treaty issues, most of which are highly technical.

A report from U.S. Ambassador to Moscow Jack Matlock, who saw Soviet Foreign Minister Eduard Shevardnadze there Monday, did nothing to allay the administration's concern about developments in the Baltics and the other Soviet republics. Shevardnadze, who remains in office pending selection of a successor, resigned Dec. 20 expressing fear about a move toward dictatorship in the Soviet Union. Officials here said Shevardnadze may have been reacting to inside information about a crackdown on nationality groups, a particularly sensitive issue for him because he is a native of Georgia.

Matlock reiterated the U.S. concern about a crackdown yesterday in a telephone conversation with the Soviet Foreign Ministry, according to State Department spokesman Richard Boucher.

A State Department official noted that Soviet military authorities have set a deadline of Jan. 13, which is two days before the United Nations deadline for Iraq to leave Kuwait, for Estonia and Latvia to begin enforcing Soviet conscription laws. No deadlines have been announced for other areas, suggesting that those two Baltic republics could see the first possible military confrontations.