WASHINGTON - President Donald Trump has fired his White House personal assistant John McEntee, who had been with the president since early in his campaign, an administration official confirmed on Tuesday (March 13).

The president's campaign then announced McEntee will rejoin the reelection campaign as a senior adviser of operations, Washington Post reported.

McEntee is the latest in a series of departures by West Wing officials, including communications director Hope Hicks and staff secretary Rob Porter.

The Wall Street Journal first reported on the firing, citing an unspecified security issue.

A source quoted by CNN said McEntee was fired because he is currently under investigation by the Department of Homeland Security for serious financial crimes. The charges are not related to the President, the source said.

Trump has had a record rate of turnover in his senior staff. Before McEntee's departure, 43 per cent of the president's executive staff had left in the first 13 1/2 months.

McEntee's departure was overshadowed by the news that Trump fired Secretary of State Rex Tillerson and nominated CIA Director Mike Pompeo to replace him.

Gina Haspel - the deputy director at the CIA - will succeed Pompeo at the CIA, becoming the first woman to run the spy agency, if confirmed.

Also Tuesday, the Trump campaign announced that Katrina Pierson, who served as the campaign's 2016 national spokeswoman, will rejoin the effort as a senior adviser.

"We need the help of proven leaders such as Katrina and John to promote the President's growing portfolio of achievements across the country," campaign manager Brad Parscale said in a statement.