The U.S. military Tuesday said it supported a plan to establish a demilitarized zone in northern Syria that would separate rebels in their last stronghold from advancing government forces. The agreement to create a buffer zone was worked out Monday in a meeting between Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan held in Sochi, Russia. Russia’s defense minister said that under the agreement, Syria would refrain from launching an offensive on Idlib Province, the last major rebel stronghold.