TEHRAN, Young Journalists Club (YJC) - "The president is grateful for Tom's commitment to the safety and security of our great country," White House spokeswoman Sarah Sanders said in a statement on Tuesday.
“Tom 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. President Trump thanks him for his patriotic service and wishes him well," Sanders added.
The announcement came one day after John Bolton took over as Trump's fourth national security adviser.
On Monday, US National Security Council spokesman Michael Anton said he was quitting his post at the Trump administration amid a shake-up of his national security and foreign policy teams.
Just recently, national security adviser H.R. McMaster resigned from his post.
The White House has recently seen a serious shake-up with McMaster and Secretary of State Rex Tillerson gone.
The long list of dismissals and resignations in the Trump administration reveals the chaotic play of power inside the White House, run by a former celebrity businessman.