Brett McGurk's decision to accelerate his departure from the Trump administration comes on the heels of Secretary of Defense James Mattis' resignation earlier this week.
In an interview with NPR, Secretary of State Mike Pompeo expanded on remarks by President Trump, who declared the U.S. had "won against ISIS" amid news that the Pentagon would pull troops from Syria.
Kurdish officials in northeastern Syria say they are holding 550 foreign women whom they captured after defeating ISIS, as well as about 1,200 foreign children.
The city's slow recovery after ISIS rule is causing anger among residents who say they're left with little help from the countries that destroyed Raqqa.
Afghan officials declared success after American forces targeted Abu Sayeed Orakzai. The U.S. military says the strike took place near the border with Pakistan.
More than 500 foreign women are accused of being married to ISIS fighters and are standing trial in Iraq. The women have more than 1,100 young children. All face a perilous future.
U.S.-backed Iraqi forces drove the militants out of the city eight months ago, but residents say hardly any efforts are in place to rebuild homes after airstrikes and explosions toppled them.
Raqqa may be cleared of ISIS fighters, but hidden throughout the city are thousands of hidden bombs. U.S. special forces and Syrians are training young men to disarm them.