The Supreme Court has given President Donald Trump the go-ahead to unilaterally withhold $4 billion in foreign aid previously appropriated by Congress, a crucial milestone in an intense legal battle over the constitutional power of the purse.

The high court’s ruling Friday, issued over the dissent of the three liberal justices, signals Trump has the upper hand in that battle. The decision effectively blessed Trump’s “pocket rescission” — a controversial maneuver in which the president withheld the funds toward the end of the fiscal year so that the money could not be spent even if Congress did not approve the rescission.

That tactic was designed to circumvent the usual process for a rescission of funds: a special request from the president followed by a 45-day period in which Congress must agree to the request for it to become effective.

The ruling comes as the federal government hurtles toward a Sept. 30 deadline to avert a government shutdown, and it could make bipartisan negotiations an even taller order. Democrats wary of cutting deals with GOP leaders must now face the more concrete prospect that Trump could again refuse to spend funds appropriated by Congress.

The ruling — issued in a short, unsigned order on the court’s emergency docket — is not a final decision on the broader question of the president’s power to unilaterally “impound” congressionally appropriated funding.

Rather, the majority wrote that, based on its “preliminary view” of the matter, the Trump administration had made a strong enough argument that the foreign-aid groups who sued to restore the funds did not have a legal right to bring a lawsuit under the relevant federal statutes.

The majority also suggested that Trump’s arguments in support of the budgetary move were bolstered because the funds were related to foreign policy, an area where presidents are understood to have wide latitude.

Litigation over Trump’s cancellation of foreign-aid money may continue in lower courts, and the impoundment question may return to the Supreme Court in the coming months.

Prior presidents have claimed the power to unilaterally impound congressionally appropriated funds, but they’ve rarely deployed it and its legality has never been resolved by the Supreme Court. During his 2024 campaign for the White House, Trump vowed to make aggressive use of the claimed authority and to challenge Congress’ efforts to limit it.

Trump’s ability to hold back congressionally approved funding has emerged as a key issue in the pending shutdown fight. Among the concessions Democrats are seeking from Republicans is a firm guarantee that the administration will in fact spend what Congress agrees to appropriate.

In the litigation over Trump’s unilateral cuts to foreign aid, a federal district judge has issued several rulings in favor of the aid groups and contractors challenging the cuts. The judge, Biden appointee Amir Ali, ordered the administration to prepare to spend the $4 billion at issue — an order that prompted the administration’s emergency appeal to the Supreme Court.

Solicitor General D. John Sauer, representing the administration, warned the court that requiring spending of the funds would force executive branch officials into negotiations with foreign governments about doing so.

Justice Elena Kagan, writing for the dissenters, suggested that the administration’s stance shortchanged the role the Constitution gives to Congress over spending.

“That is just the price of living under a Constitution that gives Congress the power to make spending decisions through the enactment of appropriations laws,” Kagan wrote, joined by Justices Sonia Sotomayor and Ketanji Brown Jackson. “If those laws require obligation of the money, and if Congress has not by rescission or other action relieved the Executive of that duty, then the Executive must comply.”

Kagan also lamented the court’s willingness to side with Trump on a short timeframe with minimal briefing. Friday’s ruling is the latest of about 20 short-term victories that Trump has obtained on the court’s emergency docket this year, prompting complaints from the three liberal justices that the court’s conservative majority is rushing to side with Trump on novel and consequential issues.

“In a few weeks’ time — when we turn to our regular docket — we will decide cases of far less import with far more process and reflection,” she wrote.

The mechanism Trump used to cancel the funding was created by the 1974 Impoundment Control Act, a federal law created in the wake of fierce battles between Congress and President Richard Nixon over his refusal to spend appropriated funds.

The Trump administration argued that the foreign-aid groups did not have the right to sue under the law, and that only the U.S. comptroller general could do so.

The court appeared to sympathize with that argument Friday, ruling that the administration “at this early stage, has made a sufficient showing that the Impoundment Control Act precludes” the lawsuit brought by the aid groups.

In her dissent, Kagan disputed the notion that only the comptroller general — who is the head of the congressional Government Accountability Office — could sue, citing a different provision of the law protecting “the claims or defenses of any party to litigation concerning any impoundment.”

The implication of the ruling may allow Trump to withhold congressional funding so long as the comptroller general does not act. The sitting comptroller general, Gene Dodaro, has identified multiple instances where the administration has illegally withheld funding but has not brought a lawsuit. His 15-year term ends in December, and Trump will play a role in nominating his successor.