Rear Admiral Kevin Sweeney becomes third senior Pentagon official to resign in recent weeks.
Rear Admiral Kevin Sweeney (Picture: US Department of Defense).
Rear Admiral Kevin Sweeney has resigned as Chief of Staff to the US Department of Defense, becoming the third senior Pentagon official to quit since President Donald Trump announced plans to pull US troops out of Syria.
Rear Admiral Sweeney had held the position since January 2017.
He said in a statement: "After two years in the Pentagon, I've decided the time is right to return to the private sector.
"It has been an honour to serve again alongside the men and women of the Department of Defense."
President Trump's shock announcement on Syria resulted in Defence Secretary General James Mattis resigning.
In his resignation letter, General Mattis wrote: "You (President Trump) have a right to have a Secretary of Defense whose views are better aligned with yours.
"While the US remains the indispensable nation in the free world, we cannot protect our interests or serve that role effectively without maintaining strong alliances and showing respect to those allies."
Department spokeswoman Dana White also stepped down following President Trump's announcement.