WASHINGTON (Reuters) - The U.S. House of Representatives passed a $700 billion defense policy bill on Tuesday, backing President Donald Trump’s call for a bigger, stronger military, but failing to decide how to fund the massive spending increase.

Rep. Mac Thornberry (R-TX) speaks at a press conference about the National Defense Authorization Act in Washington, U.S., October 25, 2017. REUTERS/Aaron P. Bernstein

The Republican-controlled House voted 356-70 for the annual National Defense Authorization Act, or NDAA, which authorizes the level of defense spending and sets policies controlling how the money is spent.

But the legislation defies spending caps set in the 2011 Budget Control Act and there is no clear plan from Congress on how to provide the money for the Pentagon. The 2018 NDAA authorizes $634 billion in base defense spending, for such things as buying weapons and paying the troops, well above the $549 billion allowed under the previous legislation.

The NDAA also includes provisions such as an increase in active troop levels by more than 16,000, and states that climate change is a national security threat.

The defense policy bill will become law if it passes the Republican-controlled Senate and is signed into law by the president, as expected. But spending will nonetheless be cut automatically if Congress cannot come up with a deal to resolve the gap in funding.

Representative Adam Smith, the top Democrat on the House Armed Services Committee, said Congress’ failure to address the issue makes life more difficult for military leaders because they cannot plan in advance.

“This defense bill is $72 billion over the budget caps, so if we don’t eliminate or raise the budget caps, that additional money will go away and leave us once again in the land of uncertainty for the Department of Defense,” he said.

Representative Mac Thornberry, the House Armed Service Committee’s Republican chairman, said Congress needed to pass an appropriations bill to allow for the $700 billion.

“Securing those appropriations must be Congress’ top priority before the year ends,” Thornberry said in a statement.

The NDAA also includes about $66 billion in special war funding, which is exempt from the so-called sequestration cap.

The measure passed by the House on Tuesday is a compromise reached by House and Senate negotiators between separate versions of the bill approved in the chambers earlier this year.

However, a budget fight is expected because Senate Democrats may not agree to big increases in funds for the military if spending caps on non-defense programs are not also eased. The Republican majority in the Senate is so small that most legislation cannot pass without some Democratic votes.