WASHINGTON (AP) — White House national security adviser John Bolton has selected a new deputy.

Bolton announced Friday that Charles Kupperman, a longtime colleague dating back to the Reagan administration, would serve as President Donald Trump's new deputy national security adviser.

Bolton says in a statement that Kupperman has been an adviser to him for more than 30 years. He adds, "Charlie's extensive expertise in defense, arms control and aerospace will help further President Trump's national security agenda."

Kupperman, a former executive for defense contractors Boeing and Lockheed Martin, is the fourth person to hold the role under Trump.

Bolton's previous deputy, Mira Ricardel, left last year after First Lady Melania Trump's office issued a public statement calling for her ouster.

Trump's administration has set records for turnover at all staff levels.