WASHINGTON - US President Donald Trump's homeland security adviser, Tom Bossert, has resigned, the White House confirmed Tuesday.

"The president is grateful for Tom's commitment to the safety and security of our great country," White House Press Secretary Sarah Sanders said in a statement.

The 43-year-old adviser led "the White House's efforts to protect the homeland from terrorist threats, strengthen our cyber defenses, and respond to an unprecedented series of natural disasters," she said.

Sanders said that Trump "thanks him for his patriotic service and wishes him well," but she did not give a reason for Bossert's departure.

Bossert, who previously served in George W. Bush's administration, was tapped to be assistant to the president for homeland security and counterterrorism in December, 2016.

Last weekend, Bossert represented the administration on television to talk about the US response to an alleged chemical attack in Syria.

Bossert's resignation is in the latest high-level departure from the White House after the replacement of the secretary of state last month.

It comes a day after John Bolton took over as Trump's new national security adviser after the departure of H.R. McMaster in March.