The Kurdish-led administration in northern Syria has said the Syrian army would deploy along the entire length of the border as part of the agreement to try to halt Turkey’s operation in the region.
Syrian state media earlier reported that government forces had been deployed to the north.
It follows the US decision to pull all its remaining troops from the area over the “untenable” situation there. The Turkish assault, launched last week, is aimed at forcing Kurdish forces from along the border area.
This deployment would assist the SDF in countering “this aggression and liberating the areas that the Turkish army and mercenaries had entered”, it said in a statement.
Areas under the control of the Kurdish-led Syrian Democratic Forces (SDF), the main US ally in the area, have come under heavy bombardment over the weekend, with Turkey making gains in two key border towns.
Dozens of civilians and fighters have been killed on both sides.
Amid fears of the resurgence of the Islamic State (IS) group as a result of the fighting, Kurdish officials said on Sunday that nearly 800 relatives of foreign IS members had escaped from Ain Issa, a camp in the north, as clashes raged nearby.
Turkey’s Syria offensive explained in four maps
The Turkish offensive and US withdrawal have drawn an international outcry, as the SDF were the main Western allies in the battle against IS in Syria.
But Turkey views elements of the Kurdish groups within the force as terrorists and says it wants to drive them away from a “safe zone” reaching 30km into Syria.
President Recep Tayyip Erdogan hopes to resettle up to two million Syrian refugees currently in Turkey within the zone. Many of them are not Kurds. Critics have warned this could lead to the ethnic cleansing of the local Kurdish population.
The deal represents a significant shift in alliances for the Kurds, after losing the military protection of their long-term US partners in the area.
It is not yet known what the Syrian government has committed to.