The US is significantly boosting troop numbers in Afghanistan
US President Barack Obama has asked Congress for an extra $83.4bn (£56.7bn) to fund operations in Iraq and Afghanistan this year.
In his official letter to the House, he said the request was his "last planned war supplemental [payment]".
The supplementary money is needed to pay for the new Afghan strategy and the reduction of combat troops in Iraq.
Mr Obama opposed special troop funding while a member of Congress under the Bush administration.
The sum breaks down into $75.8bn for the Pentagon and more than $7bn in foreign aid, including $1.8bn for Pakistan, the Associated Press news agency reports.
It would push the war money approved for 2009 to about $150bn. The totals were $171bn for 2007 and $188bn for 2008, when George W Bush was in the White House.
According to the non-partisan Congressional Research Service, the new money will bring the cost of the wars in Iraq and Afghanistan since 9/11 to almost $1tn.
Mr Obama's request is likely to win easy approval from the Democratic-controlled Congress despite frustration among some liberals over the pace of troop withdrawals, AP adds.
The outlines of the request were provided in documents presented at a private Congressional briefing. The funds are meant to pay for an average force level in Iraq of 140,000 troops, with force levels in Afghanistan rising to 45,000.
The request is a "supplemental", meaning it falls outside the usual budgetary process.
"The Taleban is resurgent and al-Qaeda threatens America from its safe haven along the Afghan-Pakistan border," Mr Obama wrote.
Nearly 95% of the money would, Mr Obama said, go to the Pentagon to "help the people of Iraq to take responsibility for their own future, and work to disrupt, dismantle, and defeat al-Qaeda in Pakistan and Afghanistan".
The rest of the money would be used to confront other threats to US security, from "securing loose nuclear weapons to combating fear and want under repressive regimes".
"As I noted when first I introduced my budget in February," Mr Obama continued in his letter, "this is the last planned war supplemental."
He noted that since 9/11, Congress had passed 17 separate emergency funding bills totalling $822.1bn for the wars in Iraq and Afghanistan.
"We must break that recent tradition and include future military costs in the regular budget so that we have an honest, more accurate and fiscally responsible estimate of federal spending," Mr Obama said.
In a statement, Democratic House Speaker Nancy Pelosi said Congress would review Mr Obama's request and "engage in a dialogue with the administration on appropriate benchmarks to measure the success of our investment".
House Republican leader John Boehner suggested Republicans would be likely to support the funding request.