A "gratified" President Bush said yesterday the vote in Congress authorizing war in the Persian Gulf sends the "clearest message to Iraq it cannot scorn the Jan. 15th deadline" for withdrawal from Kuwait.

Bush said if there must be war it would come "sooner rather than later."

"We have now closed ranks behind a clear signal of our determination and our resolve to implement the United Nations resolutions," Bush said just moments after the final congressional vote giving him the authority to unleash American military forces against Iraq.

The president indicated he held out little hope for last-minute diplomatic resolution of the crisis, but appeared to soften his language on whether an international peace conference on the Middle East might be part of an overall settlement.

Repeating his position that there should be "no linkage" between Iraq's withdrawal from Kuwait and such a peace conference to deal with the Arab-Israeli problem, Bush added, "I guess I'd say it depends how it's put forward."

United Nations Secretary General Javier Perez de Cuellar, who is expected to meet with Iraqi President Saddam Hussein in Baghdad today, is believed to be carrying a set of proposals that includes convening such a conference at a later point.

Bush also said he supports another proposal the U.N. envoy is reportedly carrying: creation of a U.N. peacekeeping force in the gulf. But the president said he had not discussed the package with Perez de Cuellar in phone calls this week.

Bush also revealed that the Soviet Union may seek to send an emissary to Baghdad after the Perez de Cuellar mission, but ruled out diplomatic initiatives after Jan. 15. "There is no flexibility on our part" about extending the deadline, he said.

Soviet President Mikhail Gorbachev spoke with Bush Friday about his ideas for a diplomatic initiative, but administration officials said privately they see nothing new in them and have little hope that they provide the formula for a peaceful settlement of the crisis.

With the deadline just three days away, Bush said, the "sudden commencement" of a "rapid, massive withdrawal" of Iraqi forces from Kuwait might yet avert war. But he warned again that Saddam must comply with the U.N. demand for complete withdrawal without conditions and ruled out compromise.

"We did not plan for war," Bush said, "nor do we seek war. But if conflict is thrust upon us, we are ready and we are determined."

Yesterday, the White House released Bush's letter to Saddam, which Iraqi Foreign Minister Tariq Aziz refused to accept from Secretary of State James A. Baker III during their meeting in Geneva.

In the letter, Bush warned Saddam that he will "pay a terrible price" if war breaks out. "What is at issue here is not the future of Kuwait -- it will be free, its government will be restored -- but rather the future of Iraq," Bush wrote.

He told Saddam that his military would face "destruction" and there would be "certain calamity" for the Iraqi people, adding that the United States would "not tolerate" the use of chemical or biological weapons or acts of terrorism. "There can be no reward for aggression," Bush wrote. "Nor will there be any negotiation." But he told Saddam that by withdrawing from Kuwait, Iraq could "gain the opportunity to rejoin the international community."

The president returned to the White House from Camp David shortly before Congress concluded its historic debate. Calling the deliberation "properly somber," Bush said the three-day debate has shown "the best of the United States Congress at work." Bush said he had watched parts of the debate and praised the lawmakers for the absence of rancor.

He added that while he was gratified by the outcome, there was none of the "exhilaration and joy, pleasure" that normally comes when a president wins a major legislative victory.

"The compassion and the concern, the angst of these members, whether they agreed with me or not, came through loud and clear," he said. "And so, I guess, I shared the emotion. I want peace. I want to see a peaceful resolution, and I could identify with those, whether they were on the side that was supporting the administration or the other, for those who were really making fervent appeals for peace."