The American Senate is poised to pass a defence policy bill that pumps $700 billion into the Pentagon budget, expands US missile defences in response to North Korea’s growing hostility and refuses to allow excess military bases to be closed.

The legislation is expected to be approved on Monday by a wide margin in another burst of bipartisanship amid President Donald Trump’s push for cooperation with congressional Democrats.

The 1,215-page measure defies a number of White House objections, but Trump hasn not threatened to veto the measure. The bill helps him honour a pledge to boost military spending by tens of billions of dollars.

Senator John McCain, the Armed Services Committee chairman battling an aggressive type of brain cancer, has guided the bill toward passage over the last week as he railed against Washington gridlock and political gamesmanship.

But McCain, R-Ariz, could not quell disputes among his colleagues over several contentious amendments that so far have been blocked from votes and failed to be added to the bill.

Among them is a proposal by Senators Kirsten Gillibrand, D-NY, and Susan Collins, R-Maine, that would have protected transgender service members from being kicked out of the armed forces. Another amendment, from Senator Mike Lee, R-Utah, would prevent the government from detaining indefinitely US citizens apprehended on American soil who are suspected of supporting a terrorist group.

Approved by the Armed Services Committee by a vote of 27 -0 in late June, the Senate bill would provide USD 640 billion for core Pentagon operations, such as buying weapons and paying troops, and another USD 60 billion for wartime missions in Afghanistan, Iraq, Syria and elsewhere.

Trump’s budget request sought USD 603 billion for basic functions and USD 65 billion for overseas missions.

With North Korea’s nuclear program a clear threat to the US and its allies, the bill would provide USD 8.5 billion to strengthen US missile and defence systems. That is USD 630 million more than the Trump administration sought for those programmes, according to a committee analysis.

North Korea last week conducted its longest-ever test flight of a ballistic missile, firing an intermediate-range weapon over US ally Japan into the northern Pacific Ocean. The launch signaled both defiance of its rivals and a significant technological advance.

The legislation requires the Defence Department to deploy up to 14 additional ground-based interceptors at Fort Greely, Alaska, that will expand to 58 the number of interceptors designed to destroy incoming warheads. The department also is tasked with finding a storage site for as many as 14 spare interceptors, and senators envision an eventual arsenal of 100 with additional missile fields in the Midwest and on the East Coast.

The White House, in a statement issued earlier this month, called the order for more interceptors “premature” given the Pentagon’s ongoing review of missile defence programmes.

Although the bill calls for more military spending than at any point during the wars in Iraq and Afghanistan, major hurdles need to be cleared before all the extra money materialises. Congress would have to roll back a 2011 law that set strict limits on military spending. That is a tall order in the Senate, where support from Democrats will be necessary to get the 60 votes required to lift the so-called budget caps.

As their House counterparts did, the Senate bill rejects Defence Secretary Jim Mattis’ plan to launch a new round of base closings starting in 2021. He told lawmakers in June that closing excess installations would save USD 10 billion over a five-year period. Mattis said the savings could be used to acquire four nuclear submarines or dozens of jet fighters. But military installations are prized possessions in states and lawmakers refused to go along.