National security adviser Mike Waltz is leaving his White House post, although soon after reports about his departure were published, President Trump announced he plans to nominate him to be ambassador to the United Nations.

National security adviser Mike Waltz is expected to depart from the Trump administration in the coming days, two sources familiar with the matter told CNN, the first major staff shakeup since the president took office in January.

Mike Waltz will be nominated as U.S. ambassador to the U.N., while Secretary of State Marco Rubio will take on the added role of interim national security adviser.