Trump transition live updates: In a flurry of nominations, Trump announces 7 picks

Senate Minority Leader Mitch McConnell, who earlier said he would not be the party’s Senate leader in the new Congress, announced Thursday he will be chairman of the Senate Rules Committee and the Defense Appropriations subcommittee when Republicans take control of the Senate in January.

Both positions are significant, given McConnell’s strained relationship with Trump.

The appointment to the Rules committee, which maintains the operating procedures of the Senate, is particularly interesting at a time when Trump has suggested he’s interested in pushing the boundaries of the Senate’s normal operating procedure.

In his statement, McConnell said, “Defending the Senate as an institution and protecting the right to political speech in our elections remain among my longest-standing priorities.”

McConnell could be instrumental in defense of the Senate filibuster or, potentially, recess appointments, which Trump has said he might use to circumvent Senate approval of some of his Cabinet picks, though party leadership still has the final say in these matters.

The appointment to lead the defense appropriations subcommittee is also significant for McConnell, who has said he sees advocating on behalf of U.S. self-defense and the defense of U.S. allies as a critical part of his role post-leadership. He could use the post to advocate for additional funding for Ukraine.

“America’s national security interests face the gravest array of threats since the Second World War. At this critical moment, a new Senate Republican majority has a responsibility to secure the future of U.S. leadership and primacy. I intend to play an active role in this urgent mission as Chairman of the Senate Appropriations Subcommittee on Defense, and I look forward to working closely with incoming Chair Susan Collins to accomplish our shared goal,” McConnell said in his statement.

-ABC News’ Allison Pecorin

House Speaker Mike Johnson said Matt Gaetz "has a bright future ahead of him" after the former congressman withdrew his name from attorney general consideration.

"I've worked closely with Matt for eight years. He is an America First fighter -- dedicated to ending the weaponization of the Department of Justice which, after the abuses of the Biden-Harris Administration, needs serious reform," Johnson said on X.

Vice President-elect JD Vance responded to Matt Gaetz's withdrawal from consideration to be attorney general, saying on X he is "extremely grateful for the work Matt put into the nomination process."

"He made his decision to withdraw entirely out of respect for President Trump's administration. Matt is a patriot and I look forward to seeing what he does next," Vance, who joined Gaetz while he met with Republican senators on Capitol Hill Wednesday, added.

Some of the Republican senators thought to be opposed to the selection of Matt Gaetz for attorney general because of obstacles to his confirmation openly praised his decision to step aside.

"I think that was an excellent move on behalf of the incoming President," Minority Leader Mitch McConnell said -- though it's not clear if Trump directed Gaetz to withdraw.

"I think it was a sound decision. I think it was important," said Sen. Lisa Murkowski, who had been among those publicly projecting serious concern about Gaetz's nomination.

Asked if she was relieved, Murkowski said, "I am. I think it was the right decision."

Sen. Mike Rounds, who had also expressed some concerns about Gaetz, said the move to withdraw was the "right decision to make."

"There was perhaps some information out there that the president was not aware of when he made the original recommendation. Part of this process is, the information comes out, and then at that point, as people re-evaluate or evaluate, you know, the president or the individual candidate may decide it's not the right time to pursue the nomination," Rounds said. "It may very well have been because of advice from the Senate rather than consent from the Senate."

Not all senators were as open on their views.

"That's obviously a decision he came to, and I think everybody had to make a decision that's good for them and their family. And for whatever reason he decided not to pursue it," Sen. John Thune, the incoming Republican leader, said.

When pressed on whether he felt it was the right choice, he said, "We respect his decision."

Many Republican senators said they were taken by surprise.

"I learned about it the same way everyone else did, by reading the announcement," Sen. Ted Cruz, who sits on the Senate Judiciary Committee and met with Gaetz on Wednesday, said.

-ABC News' Allison Pecorin