Turkish President Tayyip Erdogan said on Wednesday that Kurdish militants in Syria will either lay down their weapons or "be buried", amid hostilities between Turkey-backed Syrian fighters and the militants since the fall of Bashar al-Assad this month.

Kurdish-led fighters in Syria, known as the Syrian Democratic Forces, say they have launched a counter-offensive against the Ankara-backed Syrian National Army to take back areas near Syria’s northern border with Turkey.

Turkey said Syria’s new rebel government agrees with Ankara on the need to dismantle Kurdish military forces — a critical US ally in the northern region of Syria — as countries rush to shape the future of the region after the downfall of the Assad regime.

The Turkish military killed 21 Kurdish militants in northern Syria and Iraq, the defence ministry said on Wednesday.

Syria is ablaze as NATO-aligned forces clash over control in a deadly new conflict. Turkish forces launched a series of attacks targeting U.S.-backed fighters, leaving over 20 dead. Meanwhile, escalating tensions hint at deeper geopolitical rivalries unfolding on the ground.