President Donald Trump has moved to unilaterally cancel nearly $5 billion in congressionally approved foreign aid, deploying a budget maneuver known as a “pocket rescission” that has not been attempted since 1977. In a letter sent late Thursday to House Speaker Mike Johnson, the White House Office of Management and Budget said it would withhold funding for 15 international programs, including roughly $3.2 billion in US Agency for International Development projects and about $838 million earmarked for United Nations peacekeeping operations. The administration argues that the 1974 Congressional Budget and Impoundment Control Act permits the president to freeze the money for 45 days, long enough for it to lapse when the fiscal year ends on Sept. 30. The move has intensified a long-running clash over Congress’s power of the purse. Senate Majority Leader Chuck Schumer called the rescission illegal and warned that Democrats could tie the issue to forthcoming spending bills, heightening the risk of a government shutdown. Republican Senator Susan Collins also voiced concern, signaling bipartisan unease with the approach. Legal challenges are expected. The Government Accountability Office maintains that pocket rescissions violate the 1974 law, while the administration cites precedents set during the Ford and Carter presidencies. The funds had been frozen in litigation until the DC Circuit Court of Appeals lifted an injunction earlier in the day, clearing the way for what could become a major constitutional test of executive spending authority.