Russia has encouraged Turkey and Syria to refer to the 1998 treaty to deal with security concerns along their shared borders in the wake of a planned U.S troop withdrawal from northern Syria. It wasn't immediately clear if and how Moscow would reconcile differences between Turkey and Syria, who have been openly hostile toward each other since the start of the Syrian civil war.
A Syrian Foreign Ministry statement said Turkey has violated the agreement since 2011 with its support of armed opposition fighters, then its ensuing military incursions into Syria since 2016, which it called "occupation." Turkey has sent troops into Syria and backed armed groups in a bid to uproot Islamic State group militants and Syrian Kurdish militias it labels "terrorist organizations" from near its borders.
"Reactivating this treaty takes place by restoring the situations on the borders between the two countries to how they were," said the Syrian Foreign Ministry, calling on Turkey to withdraw and stop arming opposition groups. "This would enable the two countries to activate the agreement that guarantees the security and safety of the borders between them."
Turkey says the 1998 treaty gives it the right to move into Syria, justifying its troop deployment in the country and a possible new offensive designed to push out the Syrian Kurdish militia that Ankara considers to be an existential threat.
In a meeting between Russian and Turkish presidents this week, Vladimir Putin signaled his country was willing to accommodate Turkey's concerns but encouraged Ankara to use the 1998 treaty with Syria to help ensure border security.
Meanwhile, Russia has been supportive of Damascus regaining control of territories after U.S. troops withdraw and has backed dialogue between the Syrian government and the Kurdish militia. The U.S. has maintained a military presence in northeastern Syria to battle Islamic State group militants with support from the local Kurdish fighters. The plan to withdraw triggered the scramble for how to fill their absence.
Speaking in southeastern Turkey on Saturday, Erdogan said his country is committed to the 1998 treaty and has worked to implement it. The Adana protocol was signed in October 1998 following heightened tensions between Turkey and Syria the Kurdish militants operating across the borders. Syria promised to root out the Kurdistan Workers' Party, or PKK, waging an insurgency in Turkey after allowing them to operate from there since the 1980s.
With the agreement, Syria declared the PKK a terror organization and promised to prevent attacks against Turkey emanating from its territories. The agreement also promised close security cooperation between Turkey and Syria.
Associated Press writers Sarah El Deeb in Beirut and Zeynep Bilginsoy in Istanbul contributed to this report.