Senator Mark O. Hatfield, the Oregon Republican who is chairman of the Appropriations Committee, said Republicans were prepared to restore $600 to $800 million in spending as the "cornerstone of an agreement."

But Mr. Hatfield said that the President would have to deliver Democratic votes for such a compromise and that Republican support for the bill would diminish in the House and possibly in the Senate.

In the House, Representative Robert L. Livingston, who heads the Appropriations Committee, said, "If we change this bill, we are only going to make some trimming at the edge." The Louisiana Republican added that it would be difficult to persuade some Republicans, especially the freshmen, to support any compromise with the White House. "The more change that the President wants, the more votes we lose," he said.

Mr. Clinton spent his first two years in office striking deals on issues like crime and the budget rather than trying to draw rigid lines or threaten a veto. Indeed, today was the first time Mr. Clinton wielded the tool known as the President's ultimate weapon, after a period without issuing a veto that was in itself a modern record. Not since Millard T. Fillmore left the White House 142 years ago had a President waited so long to cast a veto.

But since the Republicans took control of Congress, Mr. Clinton has threatened to veto several pieces of legislation making their way through Capitol Hill, including foreign aid bills he has denounced as "isolationist," attempts to repeal last year's ban on 19 kinds of assault weapons and efforts to weaken environmental legislation, as well as plans to make the Federal food stamp program into a block grant administered by the states.

Democratic strategists say the President's veto threats have helped define for the public the difference in what the two parties stand for. "He highlights very clearly the key differences with Republicans on key issues," said Mr. Mellman. "That's very important for us."

But the White House, which believes that Mr. Clinton has never received sufficient attention for his deficit-reduction efforts, has also taken pains to make sure that the President is not perceived as a big-spending Democrat. It has sought to strike a constant theme that there is a right way and a wrong way to cut spending. And budget officials have been quietly drafting plans to balance the budget in a decade, so Mr. Clinton will have alternatives to present when Congress reaches agreement on its plan to balance the budget in seven years.