Most of the new money would pay for the war in Iraq, which has cost an estimated $250 billion since the U.S. invasion in March 2003.

The additional spending, along with other war funding the Bush administration will seek separately in its regular budget next week, would push the price tag for combat and nation-building since Sept. 11, 2001, to nearly a half-trillion dollars, approaching the inflation-adjusted cost of the 13-year Vietnam War.

The cost of military operations in 2006 is $35 billion higher than what Congress had estimated a few months ago that the Defense Department would need this year. The higher costs are occurring even as the Pentagon is planning to reduce troop levels in Iraq in coming months, reflecting the continuing wear and damage to military equipment in desert combat, the need to upgrade protection for U.S. troops and the effort to train and equip Iraqi forces.

No large-scale reconstruction projects are included in the spending, officials said.

Currently, the Defense Department says it is spending about $4.5 billion a month on the conflict in Iraq, or about $100,000 per minute.

Current spending in Afghanistan is about $800 million a month, or about $18,000 per minute.

The rising costs contrast with projections before the war. Former White House economic adviser Lawrence Lindsey predicted in late 2002 that the war would cost between $100 billion and $200 billion, drawing administration ire for offering such high estimates and eventually resigning his post.

In spring 2003, top administration officials, including Deputy Defense Secretary Paul Wolfowitz, said Iraq's vast oil reserves would help defray the costs of an extended U.S. stay. Nearly three years later, oil revenues are far below expectations and the Iraqi government is able to pay for only a fraction of its reconstruction.

The White House also told Congress on Thursday that it will ask for $18 billion in supplemental funds for Hurricane Katrina relief, bringing to $105 billion the amount the administration plans to spend on relief and rebuilding efforts along the Gulf Coast.

Donald Powell, federal coordinator for Katrina recovery, did not specify how the money would be spent. Aides said they will release details in the next few weeks. Democrats were quick to question how the money would be allocated.

"We certainly welcome additional federal assistance," said Sen. Mary Landrieu, D-La. "But I am highly concerned that the administration's proposal, which lacks details, will put more money into dysfunctional federal bureaucracies like FEMA [the Federal Emergency Management Agency] and won't adequately address urgent needs such as housing, levees and flood protection."

The war-spending plans were detailed in a conference call with reporters held by Joel Kaplan, a deputy director of the Office of Management and Budget.

Kaplan said the war-budget request would pay for military operations, training soldiers and policemen in Iraq and Afghanistan, repairing and replacing equipment, and running U.S. embassies in Iraq and Afghanistan.

Kaplan said the money also would go toward buying new equipment to help protect U.S. troops from roadside bombs, the deadliest weapon of insurgents.

The $70 billion the administration plans to seek would be added to $50 billion approved by Congress in December as an advance on 2006 expenses, making this year the most expensive yet for the wars in Iraq and Afghanistan.

In addition to the $70 billion for the remainder of 2006, Kaplan estimated an "emergency allowance" of $50 billion would be required as a "bridge fund" for war expenses anticipated in 2007.

Asked whether he believes that number is too low, given the $120 billion required for 2006, Kaplan said it was simply a "plug number" not intended to approximate the final need.

Congress has approved five emergency-spending measures since Sept. 11, 2001, and other federal money has been moved into the effort to wage battle in Iraq and Afghanistan. In all, more than $400 billion will have been set aside or spent by the end of this year.

The administration plans to seek the additional $70 billion as special "supplemental" funding, an emergency procedure outside the regular budget process that has stirred controversy on Capitol Hill.

Critics point out that the costs of the war, which enters its fourth year next month, have grown more predictable and say that the money should be requested in the regular budget rather than as supplemental funding.

In its regular budget, which will be released Monday, the administration will request a nearly 5 percent increase in funding for the Pentagon for fiscal 2007, to $439.3 billion, said a senior defense official, who spoke on condition of anonymity.

Despite the size of the supplemental budget request announced Thursday, analysts predicted it would likely pass Congress easily.

Brian Riedl, a budget specialist with the Heritage Foundation, summed it up: "Nobody wants to vote against the troops."

Material from the Chicago Tribune, The Washington Post and The Associated Press is included in this report.