House Republicans are pushing ahead with a defense budget that adds billions of dollars, boosts nuclear weapons programs and slows cost-cutting reductions in the force.

It's an election-year challenge to President Barack Obama.

Republicans argue that the Democratic president is shortchanging the military and leaving the nation vulnerable, requiring billions of dollars more for defense. The GOP abandoned the spending levels for defense and domestic programs set last summer in the deficit-cutting agreement between Obama and Congress. They want to boost military spending by $8 billion.

The overall defense bill totals $642 billion for the fiscal year beginning Oct. 1 - a base defense budget of $554 billion, including nuclear weapons spending, plus $88 billion for the war in Afghanistan and counterterrorism efforts.

The White House has threatened a veto.