WASHINGTON » Congress is knocking nearly $1 billion off President Barack Obama's request for Afghanistan's security forces and instead devoting the money to buying more mine-resistant vehicles for U.S. troops there.

The move comes as top House-Senate lawmakers are putting the finishing touches on a $626 billion Pentagon spending bill that Democratic leaders hope to clear for Obama's signature by Friday. Passage of the politically popular measure has been held up for weeks because Democratic leaders want to attach other controversial items to it.

House leaders were leaning toward an end-of-session strategy last evening of wrapping the defense measure together with a two-month extension of the government's ability to borrow. That authority is needed to avoid a default on the $12 trillion national debt, which is considered politically unthinkable.

“;We're working towards a short-term debt extension,”; said No. 2 House Democrat Steny Hoyer of Maryland.

The defense measure contains $128 billion to support Obama's February request for military operations in Iraq and Afghanistan. The president has yet to request funds for his recently announced troop increase in Afghanistan, and there is no money in the bill for that.

The package contains about $465 million to develop an alternative engine for the F-35 Joint Strike Fighter, the Air Force's multimission fighter of the future. The administration said in June it would veto the legislation if it would “;seriously disrupt”; the F-35 program, an iffy threat at best. It backpedaled from the veto threat after the program won an impressive Senate vote.

The bill contains no funds for new F-22 fighters. Defense Secretary Robert Gates staked his reputation on killing the jobs-rich but well-over-budget program, which is poorly suited for anti-insurgent battles.

The defense measure would trim $900 million from the Pentagon's $7.5 billion budget to train Afghan security forces. It would use the money to buy about 1,400 additional mine-resistance vehicles suited for rugged conditions in Afghanistan.

Lawmakers said they support training Afghan soldiers—the linchpin in the U.S. strategy to end the war. But Democratic Hawaii Sen. Daniel Inouye, chairman of the Senate Appropriations Committee, has said the Afghan government cannot use all the money until 2011. Negotiators siphoned it for armored vehicles.

The underlying defense bill is also expected to fund 10 C-17 cargo jets despite Obama's demand to cease production of the planes.

Democratic leaders had hoped the measure could carry a longer-term increase in the U.S. debt limit to prevent another vote before next year's elections.