Donald Trump has selected Florida Republican Rep. Mike Waltz to be his national security adviser as the president-elect continues to build his team ahead of his second term.

Waltz has been one of President-elect Trump’s most prominent surrogates during the 2024 campaign, leading military outreach efforts and assisting with the Veterans For Trump coalition, Fox News reported Monday eveningThe Florida congressman is the first retired Green Beret to serve in Congress and brings prior administration experience, having worked as a policy adviser to former Defense Secretaries Donald Rumsfeld and Robert Gates.

The Wall Street Journal first reported Waltz being offered the roleElevating a House lawmaker to the administration could complicate Republicans’ ability to govern the chamber, however.

Waltz represents a secure red district on the eastern Florida coast, making it unlikely to fall into Democratic hands. However, replacing a House member is a process that could take several weeks.

He’s the second GOP lawmaker to be tapped for Trump’s administration. Earlier Monday, the president-elect announced that he had picked Rep. Elise Stefanik of New York, the chamber’s fourth-ranking Republican, to be his UN ambassador.

“I am honored to nominate Chairwoman Elise Stefanik to serve in my Cabinet as U.S. Ambassador to the United Nations. Elise is an incredibly strong, tough, and smart America First fighter,” Trump said in a statement to the New York Post.