Trump transition live updates: Vance talking to senators about Gaetz support: Sources

To replace Florida Rep. Mike Waltz in the U.S. House following his selection to serve as Trump's national security adviser, state statute requires Gov. Ron DeSantis to call for a special primary and then a special election in Florida.

The special elections to fill the House seat differ from Florida's way of filling Senate seats. State law mandates that DeSantis appoint an individual to fill any Senate vacancy.

Waltz currently represents Florida's solidly red 6th Congressional District, one that hasn't been represented by a Democrat since 1989. DeSantis himself was the congressmember for the northeastern Florida seat ahead of Waltz.

ABC News has not yet reported a projection for who will have control of the House, but Waltz's impending vacancy could impact Republicans' numbers as they head toward a GOP "trifecta" in Washington.

-ABC News' Isabella Murray

Trump announced he has nominated former Arkansas Gov. Mike Huckabee to be the U.S. ambassador to Israel.

"Mike has been a great public servant, Governor, and Leader in Faith for many years," Trump said in a statement. "He loves Israel, and the people of Israel, and likewise, the people of Israel love him. Mike will work tirelessly to bring about Peace in the Middle East!"

The role, which will need to be confirmed by the Senate, will be a key appointment as tensions remain high in the Middle East.

Trump has officially announced his appointment of Florida Rep. Mike Waltz as his national security adviser.

The president-elect highlighted Waltz's military background in a statement on the appointment, noting that he is the first Green Beret to have been elected to Congress and served in the Army Special Forces for 27 years.

"Mike has been a strong champion of my America First Foreign Policy agenda, and will be a tremendous champion of our pursuit of Peace through Strength!" Trump said in a statement.

The national security adviser is appointed by the president without confirmation by the Senate.

-ABC News' Soo Rin Kim, Kelsey Walsh and Lalee Ibssa

While control of the House has not yet been projected by ABC News, Republicans are inching toward maintaining their slim majority.

But already, Trump has picked several lawmakers to serve in his administration: Rep. Elise Stefanik for United Nations ambassador and Rep. Mike Waltz for national security adviser.

Speaker Mike Johnson, asked about the issue on Tuesday, said he's spoken to Trump about it several times.

"We have a really talented Republican Congress ... Many of them can serve in important positions in the new administration. But President Trump fully understands, appreciates the math here and it's just a numbers game," Johnson said. "You know, we believe we're going to have a larger majority than we had last time."

The speaker added: "I don't expect that we will have more members leaving, but I’ll leave that up to him."