Washington DC - President Donald Trump has nominated National Security Advisor Mike Waltz to take on a new role in his administration.

On Thursday, Trump shared a post to his Truth Social, revealing that Waltz will now become the new US Ambassador to the United Nations.

He went on to add that Secretary of State Marco Rubio will replace him as National Security Advisor, "while continuing his strong leadership at the State Department."

"Together, we will continue to fight tirelessly to Make America, and the World, SAFE AGAIN," Trump added.

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Earlier that day, news broke that Waltz and his deputy, Alex Wong, were set to leave their roles, marking the first major official to leave the administration in Trump's second term.

According to Politico, multiple sources claimed special envoy Steve Witkoff was considered a top contender to replace Waltz, with other candidates including policy chief Stephen Miller, National Security senior director for counterterrorism Sebastian Gorka, and special envoy for special missions Richard Grenell.

Waltz has been under fire since last month after he accidentally added a journalist to a Signal chat between him and other administration officials, in which they openly discussed strikes against Yemen's Houthi rebels.

While the administration has not given an official explanation as to why he was moved from his original role, Waltz said in an X post that he is "deeply honored to continue my service to President Trump and our great nation."