The White House plan to trim the national debt includes selling off half of the nation’s emergency oil stockpile, part of a broad series of changes proposed by President Donald Trump to the federal government’s role in energy markets.

Trump’s first complete budget proposal, released in part on Monday, would raise $500 million in fiscal year 2018 by draining the Strategic Petroleum Reserve, and as much $16.6 billion in oil sales over the next decade.

The proposal also seeks to boost government revenues by allowing oil drilling in the Alaska National Wildlife Refuge, ending the practice of sharing oil royalties with states along the Gulf of Mexico and selling off electricity transmission lines in the West. Like much of the budget, those moves are likely to face opposition in Congress.

Presidential budget proposals typically undergo significant changes in Congress, but provide insight into White House priorities.

The Strategic Petroleum Reserve currently holds