There has been intense fighting near the Syrian town of Kobani, as Kurdish fighters desperately try to stop it from falling to ISIL jihadists who have advanced to within a kilometre.
The main Kurdish armed group in Syria has called on all Kurds in the region to prevent a massacre.
Turkey has said it will do all it can to prevent the mainly Kurdish town on its border from being overrun by the extremists who call themselves Islamic State.
Their advance comes despite bombing by US-led forces in Syria and Iraq, to the frustration of Washington.
“Defeating ISIS in the physical space will require a counter-offensive in which we will help to train those forces which will be part of that counter-offensive, we’ll help with the application of air power,” said John Allen, US Special presidential envoy for the global coalition to counter ISIL.
Despite the show of strength from Turkish forces near the Syrian border, the government has hinted that military action is not imminent.
Syria has condemned Turkey’s decision to approve cross-border raids against ISIL as an “act of aggression”.
The fighting has driven Syrian Kurds into Turkey en masse.
The UN High Commissioner for Refugees said 160,000 people had crossed the border in a few days, calling it a “dramatic humanitarian tragedy”.