The Bush administration yesterday initiated direct shipments of U.S. medical aid to the beleaguered Baltic republics of the Soviet Union in a gesture of U.S. support for them.

At the same time, Secretary of State James A. Baker III signaled that the United States would not move toward ratifying the recent conventional arms reduction treaty until controversies with the Soviet Union about application of the treaty are cleared up.

President Bush said last night that the "visible repression" of the independence movement in the Baltic states by the Soviet government threatens relations between the two superpowers and could thwart a more cooperative relationship with the Soviets until he can determine whether the actions are "an anomaly and not a new way of life."

"We've got to see that no more force will be used against these Baltic states and that there can be peaceful resolution of these questions," he told the Economic Club of New York. "Otherwise, not only will our trade relations be set back, as they are now being set back in some European countries, but the rest of our overall relationship could undergo a problem."

Bush, who praised Soviet President Mikhail Gorbachev for having "done wonderful things" and for his cooperation in the Persian Gulf, said he hoped he could avoid a rupture of relations. "But when we see repression in the Baltics, it is very hard to have business as usual."

In testimony earlier in the day before the House Foreign Affairs Committee, Baker declared, "The Soviet leadership is at a crossroads."

Saying that the perestroika reform program "cannot succeed at gunpoint," Baker criticized a recent series of what he called "unsettling events" in the Soviet Union, including the use of violence in the Baltics, restrictions on the news media and extension of military and secret police authority. But he also made clear he has not given up hope that Gorbachev will return to the path of reform.

The announcement of the U.S. medical aid to the Baltic states of Lithuania, Latvia and Estonia came from the White House less than 24 hours after the Soviet Union gave its permission for the direct distribution of the assistance in those areas. State Department officials said Baker had requested such permission last week during the Washington visit of Soviet Foreign Minister Alexander Bessmertnykh.

The shipments, bypassing Moscow, are the first direct dealings of this nature with local Baltic authorities.

White House press secretary Marlin Fitzwater said the medical shipments are intended "to demonstrate U.S. concern for the situation in the Baltic states" and are expected to begin before the end of this month. Additional medical supplies will be sent later to the Soviet Ukraine to aid victims of the 1986 Chernobyl nuclear disaster, and later to other Soviet areas experiencing acute shortages of medical supplies.

The medicines are being donated by private U.S. firms, and their distribution financed by U.S. funds. Officials said at least $10 million in medical supplies -- perhaps much more -- are expected to be donated and that shipping and distribution costs will be as much as $5 million.

On Capitol Hill, Rep. Steny H. Hoyer (D-Md.), co-chairman of the Senate-House Helsinki Commission, said a delegation of lawmakers hopes to leave this weekend for visits to the three Baltic states and a meeting with President Boris Yeltsin of the Russian Republic if Soviet authorities approve. He said no word has yet been received from Moscow, where the Supreme Soviet legislature has been asked to sponsor the U.S. congressional visit.

Baker said the administration has increased its official contacts with leaders of the Soviet republics, including the three Baltic republics. Officials said Yeltsin has been told he would be welcome and received at senior levels in Washington if he chooses to visit.

"We have had representations from the Soviet leadership about their continuing commitment to reform, to peaceful dialogue with the Baltics and to create a society ruled by law, not by force," said Baker. "Clearly, we cannot rule out the possibility that matters may still turn more for the worse, but at the same time, we must be careful not to jump to premature conclusions."

Regarding arms control, Baker said he would not recommend that the Conventional Forces in Europe (CFE) treaty, which was signed by the United States, the Soviet Union and 20 other nations in Paris on Nov. 19, be sent to the Senate for ratification until controversies with Moscow are settled over the application of the treaty.

The administration is concerned about the Soviet claim that three motorized infantry divisions be exempt from coverage of the treaty because they are classified as "coastal defense units." Naval forces are outside the scope of the treaty, which would require the Soviets to eliminate at least 19,000 weapons from Europe, compared with cuts of fewer than 3,000 weapons for all 16 NATO countries, according to the Arms Control Association.

Little or no progress was made on settling the CFE disputes in discussions with Bessmertnykh and other Soviet officials during the new foreign minister's visit here last week, U.S. officials said. The Soviet military is reported to be the driving force behind attempts to reinterpret the treaty in ways that would limit some of the big cuts required of Soviet forces.

A U.S. delegation headed by Undersecretary of State Reginald Bartholomew left Washington last night for meetings in Geneva with Soviet negotiators on strategic arms. U.S. officials still hope to complete work by early next week on the remaining substantive issues in the way of the wide-ranging strategic arms reduction treaty (START). The U.S. delegation will also raise the CFE issues with the Soviet negotiators, officials said.

Staff writer Dan Balz in New York contributed to this report.