Retired Marine Corps Gen. Anthony Zinni, who previously led U.S. Central Command, has resigned from his post at the State Department where he was tasked with resolving the conflict in Qatar.

Saudi Arabia, Bahrain, the United Arab Emirates, and Egypt severed ties with Qatar in June 2017 after it was suspected Qatar had financially assisted terrorist groups. Zinni, the most recent four-star general to depart the Trump administration, cited challenges with regional leaders as a factor contributing to his resignation.