Mike Waltz, President Donald Trump’s nominee for U.S. ambassador to the United Nations, is facing questions from lawmakers Tuesday for the first time since he was ousted as national security adviser in the weeks after he mistakenly added a journalist to a private Signal chat used to discuss sensitive military plans.

Mike Waltz, the former national security adviser who left his position in May in the wake of the Signal chat controversy in March, is facing a confirmation hearing Tuesday on Capitol Hill for his nomination as United Nations ambassador.

A confirmation hearing is underway for Trump's former national security advisor Mike Waltz, to be U.S. ambassador to the United Nations. He's facing questions from the Senate Foreign Relations Committee and is expected to be grilled over the Signal group chat controversy.