WASHINGTON—Roughly 650 U.S. troops are expected to remain in Afghanistan to provide security for diplomats after the main American military force completes its withdrawal, which is set to be largely done in the next two weeks, U.S. officials told The Associated Press. Moreover, several hundred additional American forces will remain at the Kabul airport, potentially until September. They’ll assist Turkish troops providing security, a temporary move until a more formal Turkey-led security operation is in place, the officials said Thursday. Overall, officials said the United States expects to have American and coalition military command, its leadership, and most troops out by July Fourth, or shortly after that, meeting an aspirational deadline that commanders developed months ago. The officials were not authorized to discuss details of the withdrawal and spoke to the AP on condition of anonymity. The departure of the bulk of the more than 4,000 troops that have been …