This was in February.

Senator John McCain Makes Secret Trip to Syria

"Senator John McCain (R-AZ), chairman of the Senate Armed Services Committee, made a secret trip to Kurdish territory in Syria last weekend, where he visited American military personnel. He also met with President Recep Tayyip Erdogan in Turkey on his way home.

“Senator McCain traveled to northern Syria last week to visit U.S. forces deployed there and to discuss the counter-ISIL campaign and ongoing operations to retake Raqqa. Senator McCain’s visit was a valuable opportunity to assess dynamic conditions on the ground in Syria and Iraq. President Trump has rightly ordered a review of the U.S. strategy and plans to defeat ISIL,” said a McCain spokeswoman quoted by The Hill. ...."

http://www.breitbart.com/national-security/2017/02/23/senator-mccain-makes-secret-trip-syria/