US lawmakers passed a sweeping $606 billion defense bill Thursday that exceeds a budget cap and faces a veto threat from the White House for failing to sufficiently rein in spending.

The bill would provide $518 billion for the Pentagon and an additional $88.5 billion for overseas contingency operations, specifically the war in Afghanistan and counterterrorism efforts, for the fiscal year that begins October 1.

The 2013 Defense Department spending bill had originally come in at $519 billion, an increase of $1 billion over 2012 spending, but in a surprise move just before the final vote lawmakers approved an amendment bringing the spending into line with current figures.

It's still roughly $2 billion more than President Barack Obama requested, and about $8 billion above the cap set by last year's Budget Control Act.

The Republican-controlled House of Representatives passed Thursday's bill by a vote of 326-90.

Democrats and Republicans are promising a major budget tussle this election year as the two sides square off over whether to raise taxes for wealthy Americans as well as slash federal spending in a bid to pare down the skyrocketing debt.

US lawmakers failed to reach a deal last year over how to reduce the long-term deficit by $1.2 trillion, and default spending cuts are scheduled to kick in next January that could see the defense budget slashed by an additional $50 billion in 2013.

House Appropriations Committee chairman Hal Rogers praised the bill, saying it "supports and takes care of our troops at the highest level possible, keeps America at the forefront of defense technologies, and boosts key training and readiness programs to prepare our troops for combat and peacetime missions."

"But in this environment of fiscal austerity, we must also recognize that even the Pentagon should not have carte blanche when it comes to discretionary spending," the Republican Rogers said, insisting that the bill makes "common-sense decisions" on spending cuts.

Some Democrats were keen on making even deeper cuts, but three of their proposals to slash some $23 billion from the bill were rejected.

"The bloated Pentagon budget must be addressed if we are serious about solving our nation's deficit," said congresswoman Barbara Lee, who authored several cost-saving amendments which were turned down.

But while Republicans have stood firm in their desire to see defense spending levels maintained, Lee had a partner in Republican Mick Mulvaney, who authored the measure which successfully cut the bill by $1 billion.

"Austerity to me means spending less," the Tea Party conservative said. "Total government spending will be up this year. We're still facing a $1 trillion deficit. We need to do better to get our spending under control."

The bill saw lawmakers express their disgust with Russia's stance on Syria, as they voted overwhelmingly for an amendment that ends the Pentagon's arms contract with a major Russian defense firm which provides weapons to the regime in Damascus.

House Democrat Jim Moran, who introduced the measure, lambasted the Pentagon for its contract with Rosoboronexport, which he said sells mortars, sniper rifles and attack helicopters to Syria.

The Pentagon has procured some 33 Mi-17 attack helicopters from the Russian firm and which are to be used by the Afghan military after US operations wind down in Afghanistan.

"I should think it's troubling to all of us that we are purchasing helicopters from a Russian firm that is directly complicit in the deaths of thousands of innocent Syrian men, women and children," Moran said.

The Senate will now craft its version of the defense bill, but its fate is unknown. The House has passed several spending measures but the Senate largely balks at them because they overshoot the spending agreement reached last year.