President Trump on Friday escalated his confrontation with the Senate over Todd Blanche, his nominee for attorney general, calling on the chamber to immediately confirm him and lashing out at a key Republican who is withholding his vote.

Yet even as Mr. Trump vented his anger, he appeared to validate the concerns that have fueled Republican opposition to Mr. Blanche’s confirmation, defending the idea of creating a federal fund to pay those who claim they were unfairly prosecuted by the government. That plan prompted a G.O.P. revolt in May, and Mr. Blanche had promised that it was dead.

But the two Republicans holding up his nomination, Senators John Cornyn of Texas and Thom Tillis of North Carolina, have continued to insist they need written assurances that no such payouts will occur.

Mr. Trump’s comments on Friday threw further into question when and whether the Senate can confirm Mr. Blanche.

In a social media post and at a cabinet meeting, Mr. Trump hinted that he wanted to revive the fund. Later, his lawyers said in a court filing that they planned to appeal a recent order that denounced the fund and the deal that had created it.

“Well, it is dead,” Mr. Trump said at the cabinet meeting, held at the presidential retreat, Camp David. “But, you know, I wish it weren’t, to be honest with you.”

Earlier, in a lengthy post on social media, he attacked Mr. Cornyn, saying that the senator had never had a problem with the fund until he was vanquished by a Trump-backed primary challenger.

“I will always feel that these victims of government abuse should be paid back for what they had to endure, their lives have been ruined!” Mr. Trump wrote.

Many Republican senators reacted with outrage to the creation of the fund, which was part of a deal negotiated by Mr. Blanche to settle Mr. Trump’s lawsuit against the I.R.S., and they have been eager for legal language that would formally kill it.

Mr. Cornyn and Mr. Tillis have used their spots on the Judiciary Committee as leverage, saying they will block the advancement of Mr. Blanche’s nomination unless the Justice Department formally commits itself in writing to killing the fund and narrowing the I.R.S. settlement that protects Mr. Trump and his family.

Mr. Tillis quickly seized on the president’s comments as evidence that he and Mr. Cornyn were justified in their resistance.

“The President made it clear today that the so-called Anti Weaponization Fund is still alive, which is exactly why we are attempting to formally end it,” Mr. Tillis said in a social media post responding to Mr. Trump.

Though Mr. Cornyn and Mr. Tillis have been negotiating with the Justice Department, lawmakers left Washington this week with no clear plan to vote on Mr. Blanche’s nomination.

Mr. Trump seemed to have added volatility to the discussions. On Thursday morning, he had suggested that he might temporarily withdraw Mr. Blanche’s name and leave him acting attorney general until next year, after the departures of Mr. Cornyn and Mr. Tillis, who decided not to seek re-election rather than face Trump-backed primary rivals.

But on Friday, he shifted course. In his morning diatribe, Mr. Trump taunted Mr. Cornyn for having lost his seat and insisted that “Todd Blanche, a good man, should be immediately approved as U.S. Attorney General.”

Hours later at Camp David, the president seemed to acknowledge that he was the biggest obstacle to Mr. Blanche winning confirmation.

“This has nothing to do with Todd,” he said as he was discussing the proposed Justice Department fund. “This was me.”

Mr. Cornyn and Mr. Tillis are also both seeking clear limits on the other part of the I.R.S. settlement, which gave the president, his family and his businesses broad protection from audits. Both senators want written guarantees that the audit immunity would apply only to Mr. Trump, two of his sons and the Trump Organization, and that it would be limited only to audits of past tax returns.