U.S. President Donald Trump ousted his national security adviser Mike Waltz on Thursday and named Secretary of State Marco Rubio as his interim replacement in the first major shakeup of Trump's inner circle since he took office in January.

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.

President Trump's top policy adviser, Stephen Miller, is garnering buzz inside the White House as a top candidate to be the next national security adviser, five sources familiar with the situation say.