Erdogan and Trump have a difficult agenda Wednesday that includes Turkey's decision to buy a Russian air defense system and its attack on U.S.-allied Kurdish forces in northern Syria.
At a base in eastern Syria, a senior U.S. coalition commander said Monday that American troops who remain in Syria are redeploying to bases.
A car bomb exploded in a northern Syrian town along the border with Turkey on Saturday killing 13 people, Turkey's Defense Ministry said.
Syrian Kurdish forces killed the right-hand man and spokesman for the Islamic State group in a joint operation with U.S. troops in northern Syria.
Russian military police began patrols on part of the Syrian border Wednesday, quickly moving to implement an accord with Turkey that divvies up control of northeastern Syria.
U.S. troops leaving Syria and heading to neighboring Iraq do not have permission to stay in the country, Iraq's military said Tuesday.
Residents of a Kurdish-dominated city pelted departing American military vehicles with potatoes Monday as they drove through.
Turkey's invasion of northern Syria is close to sparking a crisis at the world's biggest military alliance. But NATO has seen tense times before.
Turkey is already lashing out at the EU for criticisms of its nascent Syria offensive and has threatened to turn its 3.6 million Syrian refugees loose on Europe.
Iraq will only take back its own citizens and their families who fought with the Islamic State group in Syria, not those from other countries, Iraq's foreign minister said Thursday.