PARIS, NOV. 19 -- President Bush and Soviet President Mikhail Gorbachev concluded a lengthy meeting tonight on the Persian Gulf crisis without the Soviet leader issuing an anticipated public endorsement of a possible United Nations resolution authorizing the use of force against Iraq.

White House press secretary Marlin Fitzwater said further consultations are needed on such a resolution. "There are still people we need to talk to, that they want to talk to. And so we just simply have not reached a point of decision."

Meanwhile, Iraq said it will add 250,000 troops to the 450,000 already in Kuwait, which it invaded and annexed in August. {Details on Page A10.}

U.S. officials had suggested a Soviet endorsement would emerge after a dinner between Bush and Gorbachev tonight, but their spokesmen avoided the issue, instead stressing the leaders' agreement on the overarching policy that Iraqi President Saddam Hussein should withdraw immediately and unconditionally from Kuwait.

Soviet officials did not rule out eventual Kremlin consent for such a resolution, which would be put to a vote of the U.N. Security Council, but they emphasized the need for greater efforts to find a peaceful solution to the gulf crisis. A senior U.S. official said the United States had received assurances of support from Moscow for the concept of a use-of-force resolution, but added that the Soviets were not yet ready to publicly embrace a resolution.

Asked after his meeting Sunday with Soviet Foreign Minister Eduard Shevardnadze whether the Soviets had signed on to a new resolution, Secretary of State James A. Baker III had said, "My advice is stay tuned, and you'll get an answer tomorrow" after the meeting between the two presidents.

A senior U.S. official, seeking to explain the seeming failure to obtain the expected Soviet endorsement, said: "There is a legitimate reason that will become apparent at the end of this process. . . . I would not leap to a conclusion that the Soviets do not back a resolution. They do."

The official suggested that diplomatic negotiations with other Security Council members -- particularly the Chinese -- were affecting the timing and language of a public announcement of details of a new U.N. resolution.

The Bush-Gorbachev dinner came after a day in which both leaders, addressing the 34-nation Conference on Security and Cooperation in Europe (CSCE), joined in making Iraq's takeover of Kuwait a vital test of the international community's solidarity.

The leaders and foreign ministers of the United States, Canada and every European nation except Albaniaopened three days of meetings here at which they will discuss Europe's future at the end of the Cold War. The heads of the NATO and Warsaw Pact nations signed a historic arms control agreement.

In his address to the assembled leaders, Bush cited what he called the principles the 34 nations and the world at large should share, including a belief in the rule of law. "As we consecrate those principles here today," he said, "those same principles are grossly violated in the Persian Gulf."

Noting that Europe had suffered "so much from aggression and appeasement," Bush told the heads of state and government gathered in Paris's Kleber Center that "our success here can be neither profound nor enduring if the rule of law is shamelessly disregarded elsewhere."

Gorbachev, addressing the CSCE delegates in the same setting, said the international community's unity "and our shared concern" in the outcome of the gulf crisis tested the new world order. "We are prepared to show patience in the quest for a political solution, but we will remain firm and determined to implement the will of the United Nations," he said.

Since Iraq's invasion of Kuwait, Soviet leaders have been anxious to demonstrate their support for Western actions against Baghdad, and Western and Arab diplomats in Moscow have predicted that they eventually will agree to a U.N. resolution authorizing the use of force. The goodwill generated by Soviet cooperation over the crisis is seen in Moscow as a trump card in securing Western assistance for the crisis-ridden Soviet economy.

At the same time, the Kremlin has also sought to protect its long-term strategic interests in the Middle East by subtly distinguishing its position from that of the United States. It has placed greater emphasis on the need to keep probing for a diplomatic solution and has sent emissaries to the Middle East to try to promote a peaceful settlement.

Spokesmen for the Soviet and U.S. presidents downplayed reports of major differences over whether to submit a new resolution to the United Nations. Fitzwater said that Washington had still not decided whether to seek a resolution -- language the Bush administration has been using until it has in hand the votes it needs for Security Council approval. Officials have said the administration will not produce a draft resolution or formally propose it until it has the needed votes.

The Bush-Gorbachev session came a day after a session between Baker and Shevardnadze, part of a concerted effort the United States made during the last month to assemble the votes needed in the 15-member Security Council.

Baker is scheduled to leave here Wednesday morning in further efforts to work out language the Security Council can accept. He hopes to travel to Yemen, one of the nonaligned members of the council and -- like Cuba -- one considered most likely to oppose such a resolution.

He also is to meet with Malaysian officials before going to Colombia. By Saturday, he will have consulted with 14 of the 15 nations on the council; other officials were to have talked to the Cubans.

U.S. officials insist the resolution is not a sign that war is immiment but is another effort to make threats of force credible to Saddam.

Earlier, national security adviser Brent Scowcroft had said that such a resolution would "send {Saddam} the message that the civilized world not only condemns what he's done but is determined to rectify the situation, and that he is out of alternatives."

That the United States was unable to send such a message today, officials said, was due to complications with marshaling needed votes, not to Gorbachev's refusal to approve a resolution.

Another official said the White House had "let expectations get out of control" and insisted it was a failure of public relations, not of diplomacy. "The Soviets want to do this their way. They had a number of concerns of their own on the timing and language. But at the end of the day, they will support us and the message will be sent," said the official.

At a press briefing, senior Gorbachev aides went out of their way to emphasize the high costs of military action in the gulf and their feeling that more time is needed to explore the possibility of a peaceful solution. Vadim Zagladin, a foreign-policy adviser to the president, said war in the gulf would cause "colossal casualities in soldiers, civilians, and also economic damage," disrupting oil production for at least a decade.