US defense secretary appoints new chief of staff

US Defense Secretary Lloyd Austin on Monday tapped a senior State Department official as the Pentagon's new chief of staff.

"I am delighted that Derek Chollet will start in July as my Chief of Staff," Austin announced in a statement.

"He is one of the most distinguished, far-sighted and skillful national-security practitioners of his generation, and I am grateful to him for taking on this key assignment at such an important moment," he added.

Chollet, the current counselor of the Department of State, will replace chief of staff Kelly Magsamen, who will leave this month.

Secretary of State Antony Blinken described Chollet as a "wise counsel and steady hand" in taking on "some of the toughest" diplomatic assignments, from the Balkans and Myanmar to Pakistan and Northern Ireland, and for the past nine months in the Middle East.

Blinken named Tom Sullivan, another of his top advisers and the brother to national security adviser Jake Sullivan, to become State Department counselor.