Syrian government forces have started to reach the north of the country, hours after the government agreed to help Kurdish forces facing Turkey. Syrian state media say government forces entered Ain Issa on Monday, 30km (19 miles) south of the Turkish border. The deal came after the US, the Kurds' main ally, said it would withdraw its remaining troops from northern Syria. Turkey began an offensive in the region last week, aiming to push Kurdish forces from the border region. Areas under the control of the Kurdish-led Syrian Democratic Forces (SDF) came 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. The US announced on Sunday it was preparing to evacuate its 1,000 remaining soldiers from northern Syria. The Turkish offensive and US withdrawal have drawn an international outcry, as the SDF were the main allies of the West in the battle against the Islamic State (IS) group in Syria. There have been fears about a possible resurgence of the group and the escape of prisoners amid the instability. Turkey views elements of the Kurdish groups as terrorists and says it wants to drive them away from a "safe zone" reaching 32km 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 and critics have warned this could lead to ethnic cleansing of the local Kurdish population.