The request, which was larger than even some Pentagon officials had expected and the biggest since the Reagan-era military buildup, illustrated what administration officials said would be a focus by the president on two basic themes as he sets his agenda for the coming year: doing whatever it takes to win the war against terrorism at home and abroad and reviving the economy.

It came as Congress began its annual budget debate with a report from the Congressional Budget Office showing that the projected surplus for the next decade had dwindled to $1.6 trillion from $5.6 trillion a year ago and $3.4 trillion last summer.

The report renewed the partisan debate over the tax cut of about $1.3 trillion over 10 years, which Mr. Bush pushed through Congress last year. He did so over opposition from most Democrats, who argue that it will leave the nation short of money to address both its current needs and the long-run costs of paying Social Security and Medicare benefits to a rapidly aging population.

The budget office said the government would run deficits this year and next even in the unlikely event that Congress does not increase spending or cut taxes. And it said there does not appear to be any realistic hope of paying off the national debt within this decade, as both parties had pledged to do as recently as a year ago.

Administration officials forecast a deficit this year of $106 billion in the $2 trillion federal budget, followed by a deficit next year of $80 billion.

They said Mr. Bush's plan would call for outright cuts in some domestic programs, and would hold overall increases in spending outside of national security to very low levels.

But they said the president's budget, which will be sent to Capitol Hill on Feb. 4, would call for doubling spending on domestic security programs to more than $25 billion next year, and would set aside $90 billion in the current fiscal year and $75 billion next year for an economic recovery package built around tax cuts for individuals and businesses.

Mr. Bush acknowledged that the increase for the Pentagon "may put a strain on the budget."

But the president said the increase was necessary to continue the fight against terrorists and protect the United States from future attacks.

"We will not cut corners when it comes to the defense of our great land," Mr. Bush said in speech to the Reserve Officers Association at the Washington Hilton Hotel.

Mitchell E. Daniels Jr., the White House budget director, said Mr. Bush was seeking $38 billion in additional financing for the Pentagon on top of the $328 billion Congress authorized for the current fiscal year, an increase of 11.6 percent.

Mr. Daniels said the president also wants Congress to authorize another $10 billion reserve fund that he could draw on if necessary to pay the operational costs of the war next year. Congress has already appropriated $17 billion for that purpose this year, and the administration has signaled that it is likely to ask for more to carry it through the rest of the fiscal year, which ends Sept. 30.

The administration set out the big themes of its budget plan as Congress reconvened today and plunged immediately back into the politics of the budget and the economy.

In the Senate, Democrats and Republicans began negotiating to revive an economic stimulus package, which died at the end of last year among deep differences over what shape it should take. After meeting with Mr. Bush and Republican Congressional leaders at the White House this morning, Senator Tom Daschle of South Dakota, the Democratic majority leader, said, "There's a real opportunity to work together."

But as the day went on, the negotiations bogged down over procedure, and by tonight Republicans were sounding doubtful about making any progress on the economic package.

"It will be difficult," said Senator Trent Lott of Mississippi, the Republican minority leader, "but it is possible."

Moreover, it was clear that the two parties are likely to spar throughout this Congressional election year over the budget and the economy. Democrats suggested that they would focus in particular on whether Mr. Bush's tax cut, which they say was disproportionately tilted to the wealthy, had wrecked the government's fiscal health and limited its ability to deal with other issues.

The Congressional Budget Office said most of the blame for the swing from a $127 billion surplus last year to a projected deficit this year rested with the recession.

But it said the tax cut was the single largest cause of the sharp decline in the surplus over the next decade. It said the tax cut would eat up nearly $1.3 trillion of the surplus from now through 2011, while the weakened economy would reduce it by $929 billion and increased spending would cut it by $550 billion.

That analysis was seized on by Democrats to make their case that the tax cut had severely limited the nation's ability to deal with social and economic issues today and the costs of an aging population in the long run.

"The president told us, and told the American people, that we could have it all," said Senator Kent Conrad, Democrat of North Dakota, the chairman of the Senate Budget Committee. "Unfortunately, he was wrong, and he was wrong by a country mile. The consequences of those mistakes are enormous for the nation."

The White House defended the tax plan, saying it was the right medicine for the economy and that if the money had not been allocated to tax reductions it would have been used for more government spending.

"The purpose of government is not to keep taxes high on American people so the government can run gargantuan surpluses which get spent anyway," said Ari Fleischer, the White House spokesman.

Although the administration linked its Pentagon spending increase to the war, the additional money Mr. Bush is seeking would not go so much to the direct operating costs of the conflict in Afghanistan and other places around the world as to beefing up the nation's military more generally.

Administration officials said the increase would cover needs ranging from raising pay and improving housing to increasing the readiness of the armed forces to fight. They said it would also put the military on the way to achieving Defense Secretary Donald Rumsfeld's goal of creating a more flexible force with fewer bases and a new generation of weaponry.

In his remarks to the reserve officers, Mr. Bush cast the defense buildup as nothing less than his primary responsibility as president.

"There will be no room for misunderstanding," Mr. Bush said. "The most basic commitment of our government will be the security of our country."

Mr. Bush said that the increased spending would pay for salary increases, precision weapons, unpiloted aircraft and high-tech battlefield communications equipment, among other needs.

"The tools of modern warfare are effective," Mr. Bush said to an enthusiastic crowd. "They are expensive. But in order to win this war against terror, they are essential."

A large portion of the new spending would also go toward the procurement of such big-ticket items as warships, tanks and fighter jets, Pentagon officials said.

"This budget is to address the needs for those pieces of equipment," Susan Hansen, a Pentagon spokeswoman, said.

Ms. Hansen said that if Mr. Bush got his full request from Congress, bringing the military budget to $379 billion after accounting for some bookkeeping changes, the Pentagon would still be getting less in inflation- adjusted terms than it was in 1985, which was considered the high point of President Reagan's buildup. In 2002 dollars, the 1985 budget of $286.8 billion would be $451.8 billion, she said.

Republicans in Congress said they welcomed Mr. Bush's proposal.

"The American public are going to give the president strong support," said Senator John Warner of Virginia, the senior Republican on the Senate Armed Services Committee, "and that in turn will turn into strong bipartisan support in the Congress."

Democrats were more cautious.

"Obviously we all share an obligation to provide for the nation's defense," Mr. Conrad said, "and whatever resources are necessary we will provide. But it's also incumbent on the president to tell us how he's going to pay for this."