President Donald Trump has sent Congress an emergency request for $5.9 billion in additional defense spending, with $1.8 billion aimed at Army programs.

The request comes as lawmakers face a Dec. 8 deadline for either passing a fiscal year 2018 budget or making another temporary extension.

Trump cites three reasons for the increase.

First, additional money is needed to “detect, defeat and defend against any North Korean use of ballistic missiles against the United States, its deployed force, allies or partners,” Trump said in a Nov. 6 letter. The request includes an $884 million increase in Army missile procurement and $20.7 million more for research and development.

Second, the request includes money to pay for about 3,500 additional U.S. troops in Afghanistan. There is $48.4 million for added Army personnel expenses and $872.5 million more for added operations and maintenance costs.

The third reason for the request involves Navy costs related to two ship accidents.

Mick Mulvaney, director of the White House’s Office of Management and Budget, said about $4 billion of the overall request is needed to counter the North Korean threat and about $1.2 billion for Afghanistan.