Department of Defense chief of staff Rear Adm. Kevin Sweeney resigned on Saturday, following other high-profile Pentagon departures.

Sweeney said a statement that he "decided the time is right to return to the private sector."

Defense Secretary Jim Mattis also stepped down last month, after President Donald Trump announced he would withdraw US troops from Syria.

Another top Pentagon official announced Saturday he would step down from his role, following the resignation of Defense Secretary Jim Mattis last month and President Donald Trump's controversial decision to withdraw US troops from Syria.

Rear Adm. Kevin Sweeney, who has served as chief of staff to the Secretary of Defense since January 2017, said he would leave the department and move to the private sector.

"After two years in the Pentagon, I've decided the time is right to return to the private sector," Sweeney said in a statement. "It has been an honor to serve again alongside the men and women of the Department of Defense."

Pentagon spokeswoman Dana White also resigned earlier this week.

Read more: Trump says 'the generals' asked for more time in Syria, but he said 'Nope' because 'We've knocked them silly'

Defense Secretary Jim Mattis speaks during the 2018 POW/MIA National Recognition Day Ceremony at the Pentagon in Washington, Friday, Sept. 21, 2018. AP Photo/Susan Walsh

Mattis stepped down last month after Trump decided to withdraw troops from Syria, writing in a searing resignation letter that Trump should find a replacement whose "views are better aligned with yours" on issues like respecting allies and recognizing enemies.

Another prominent resignation following Trump's Syria decision was that of Brett McGurk, the top US official leading the 79-nation fight against ISIS. McGurk told his colleagues he could not in good conscience carry out Trump's orders to withdraw 2,000 troops.