Mike Waltz, President Donald Trump’s nominee for U.S. ambassador to the United Nations, is facing questioning Tuesday from lawmakers 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.

The former Trump national security adviser will be peppered with questions about Signal in his confirmation hearing for United Nations ambassador.

Mike Waltz, President Trump's former national security adviser, testified Tuesday at his Senate confirmation hearing to be U.S. ambassador to the United Nations.