Turkey’s president urged Russian President Vladimir Putin in a telephone call Friday to “restrain” the Syrian government and halt the humanitarian crisis unfolding in northwestern Syria as Damascus wages a military offensive against the last rebel stronghold in the country. Recep Tayyip Erdogan also called for the full implementation of a 2018 Turkish-Russian cease-fire agreement for Idlib province, which collapsed following the Russia-backed Syrian government advance, a statement from Erdogan’s office said.