“There are reinforcements on the border and within Syria in areas controlled by factions allied to Turkey. We noticed this and, yes, this is new,” SDF chief Mazloum Abdi told Reuters via phone from Syria.

Turkish officials said the army needed just a few days to be ready for a ground incursion into northern Syria, which has been attacked with howitzer long-range weapons and warplanes by the Turks for days.

The bombardments come after months of threats by Turkish President Tayyip Erdogan of a new ground invasion against Kurdish forces, which he considers to be terrorists.

Syrian Kurdish forces have received backing from Washington for years, but have also coordinated with Syria’s government and its ally Russia, both seen as foes by the United States.

Abdi said he had received “clear” assurances from both Washington and Moscow that they opposed a Turkish ground invasion but wanted something more tangible to hold back Ankara.

“We are still nervous. We need stronger, more solid statements to stop Turkey,” he said. “Turkey has announced its intent and is now feeling things out. The beginning of an invasion will depend on how it analyses the positions of other countries.”

Abdi said he would not rely on Syrian air defenses after previously telling Reuters he hoped they would help defend his forces from Ankara’s air strikes.

“Their position is weak compared to the Turkish army,” he said.

Reporter's code: 50101