The tactic -- called a pocket rescission -- has been criticized by a handful of Republican senators as it would essentially cancel congressionally authorized funding without a vote from lawmakers. The funding in question is due to expire at the end of the fiscal year on September 30.

The administration could indicate as soon as Friday what it plans to do with the remaining money that has not yet been made available to grantees. The White House Budget Office did not respond to a request for comment.

It is unclear whether Congress will object. The U.S. Constitution grants Congress control over spending, but Republicans who control both the House of Representatives and the Senate have broadly supported the administration's unilateral freezes of foreign aid and domestic spending so far.

With little Republican objection, several funding programs have been delayed for months.

The Government Accountability Office, Congress' independent watchdog agency, ruled this summer that $100 million in federal library funding -- meant to expand services on top of local dollars -- was unlawfully "impounded" and held up by the administration since March.

Funding for a Montana children's paleontology education program has remained frozen, as well as copyright and AI research, and librarian training assistance started by former Republican first lady Laura Bush, in Louisiana, Kentucky, North Carolina, South Carolina and Pennsylvania, according to grantees.

If it wanted, Congress could consider the funding cuts in committee hearings and vote on the provision. Republican senators Susan Collins from Maine and Lisa Murkowski from Alaska have objected, but other Republican lawmakers have not spoken out.

"As a Republican myself, I would love to hear more from my team on this," said Sam Helmick, president of the American Library Association.

Republicans on occasion have pushed the administration to release other frozen funding.

Ten of the Senate's 53 Republicans successfully urged White House budget director Russ Vought in July to release $6 billion in education funds, while 14 Republicans pushed to release National Institutes of Health research funding.

"We need our Republican colleagues to join us in insisting that all blocked funding gets out -- not just the programs most important to them,” Senator Patty Murray, the top Democrat on the Appropriations committee, said last month.

But other Republicans have encouraged the administration's funding delays.

"I want to spend less, not more," Senator Jim Banks, an Indiana Republican, said.

UNPRECEDENTED SCOPE

Democrats say the administration has withheld more than $420 billion in funding that was passed on a bipartisan basis in a stopgap funding bill and signed into law by Trump in March.

Emory University law professor Matthew Lawrence said the delays are unprecedented in modern times and make the government less accountable to its citizens.

“You know your representative to call and voice your concerns on spending," he said. "But if the power is President Trump’s ... I don’t know how to do that, nor do my neighbors.”

Top Republicans have often sidestepped the funding power fight and said the federal courts -- where there have been more than 60 spending-related cases -- will decide the legality of these delays.

Collins, who oversees spending as the top Republican on the Senate Appropriations Committee, says the best way to assert congressional power is to pass funding bills for the upcoming fiscal year.

But some Democrats say that is pointless if the Trump administration will not honor them.

“The budget isn’t worth the paper that we write it on if they’re just going to refuse to spend on things that matter to Democrats," Democratic Senator Chris Murphy of Connecticut told reporters.

END-OF-YEAR WITHHOLDING?

Vought, the White House budget director, has said these freezes are for “programmatic review,” a technical term that allows administration to pause and analyze spending.

However, the GAO rulings said the delays are not “permissible."

Four other program funds have been ruled as unlawfully impounded by the GAO, and it is investigating 40 other programs facing delays.

Vought told reporters in June that the pocket tactic does not require approval from Congress -- a change from the administration's prior approach, when it sought and won approval in July to cancel $9 billion for foreign aid and public media.

Collins, Murkowski and Republican Senator Mike Rounds of South Dakota have said they oppose a pocket rescission, but others have said they do not object.

"We support rescissions in whatever form they could come to us,” House Speaker Mike Johnson said in July.