Turkey agreed to suspend military operations in northern Syria for five days in return for a U.S. pledge to facilitate a pullout by Syrian Kurdish fighters, a deal President Trump hailed as “an amazing outcome,” but that some critics said mainly fulfilled Turkish goals.

Vice President Mike Pence reached the deal after five hours of talks with Turkish President Recep Tayyip Erdogan on Thursday aimed at stopping a nine-day Turkish military incursion into Kurdish-held areas in northern Syria. The U.S. and Kurds have been allies...