NATO powers might sanction Turkey over the assault on U.S. partners that has “resulted in the release of many dangerous ISIS detainees,” Defense Secretary Mark Esper said.

“Due to Turkey’s irresponsible actions, the risk to U.S. forces in northeast Syria has reached an unacceptable level,” Esper said Monday. “I will be visiting NATO next week in Brussels, where I plan to press our other NATO allies to take collective and individual diplomatic and economic measures in response to these egregious Turkish actions.”