Donald Trump's White House was hit with a fresh resignation on Tuesday as his top homeland security adviser, Tom Bossert — once a presidential favourite — announced his departure from the West Wing.

“The president is grateful for Tom's commitment to the safety and security of our great country,” White House press secretary Sarah Sanders said of the top aide's departure.

The announcement came a day after John Bolton took over as Trump's fourth national security adviser.

Bossert had been Trump's pointman on issues from counter-terror to national disasters to cyber-attacks.

His polished appearance and articulate TV style had made him a Trump favourite.

During a visit to hurricane-struck Puerto Rico last October, Trump singled out the 43-year-old for glowing praise: “Great job. Great job.”

As recently as last weekend, Bossert had represented the administration on television to talk about the the White House response to an alleged chemical weapons attack in Syria.