Trump actually can’t do that in this scenario (well he can but it’ll royally fuck him over) which is kind of funny.

If it was in the budget and money was handed out at intervals via appropriation he could just turn the faucet off, but since it’s a loan and the principal disbursed to the debtor, it falls into contract law, which is very pro-contract with probably a couple centuries of precedent.

Boiled down, only way a creditor can force a debtor to pay the remaining principal in full outside the terms of the contract is if they put an Acceleration Clause in the contract. Usually those are thrown into loans in order to recover any collateral in the event the debtor does not fulfill the terms of the contract. IE: someone quits making car payments for enough time, repo guy shows up, they auction car and apply it to the balance and demand the rest due immediately.

But acceleration clauses in practically every contract ever drafted, they’re contingent on the debtor’s performance in upholding the terms of the contract, so they almost always come into play if and only if the debtor quits performing their duties.

So without that, or if the acceleration clause isn’t applicable, debtor almost always has the right but not the obligation to pay early, creditor has no right to do the same, and creditor’s only real way to get out of the loan is to sell the rights to the debt (the servicing) to someone else, or to issue a COD (cancellation of debt). Cancellation is as it sounds, they just tear up the contract and let the debtor walk away (edit: I should note that the unfulfilled obligation is treated as taxable income for the debtor, like a gift of sorts, so they gotta pay tax on it and then walk away, but slightly pedantic). Debtor keeps whatever you gave them, debtor no longer has a contractual obligation to pay you back. It’s almost always used alongside negotiation, for example bankruptcy, they might say “if you give us this much money we’ll eat the rest of the loss”, kinda compel someone to pay that creditor first and give the creditor some way to try to wring out a couple bucks that would otherwise be a pain in the ass to collect.

So basically Trump’s only real option is to sell the debt or just do some big loan forgiveness thing lol