Trump picks Rep. Mike Waltz, a former Green Beret, as national security adviser

The Florida congressman emerged as a vocal Biden critic during Trump's campaign.

Trump called the congressman "a nationally recognized leader in National Security, a bestselling author, and an expert on the threats posed by China, Russia, Iran, and global terrorism" in a statement announcing his pick on Tuesday."

"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 his announcement.

The national security adviser does not require Senate confirmation.

Elected to the House in 2018, Waltz sits on the Intelligence, Armed Services and Foreign Affairs committees. He also serves on the House China Task Force with 13 other Republicans.

He has supported aid to Ukraine in the past, but has demanded "conditions," including increased spending from European allies, additional oversight of funds, and pairing the aid with border security measures.

Waltz, a vocal critic of the Biden administration's policy towards Ukraine who has visited the country, criticized the White House and allies for not providing Ukraine with more lethal aid -- such as MiG fighter planes from Poland -- earlier in the conflict.

Before running for elected office, Waltz served in various national security policy roles in the George W. Bush administration in the Pentagon and White House. He retired as a colonel after serving 27 years in the Army and the National Guard.