Kurdish militia commander says forces are 'ready to defend' Syrian towns from Turkey

Kurdish fighters in northern Syria are ready to take on Ankara forces, with the commander of a powerful militia force saying he will not be intimidated by Turkey threats to target in Afrin and Manbij.

People's Protection Units (YPG) chief Sipan Hemo told Kurdish media that his Kurdish fighters would "cleanse" an area in northern Syria it occupies of Ankara's "scourges".

It comes as Turkey appears to be gearing up for war in Syria, with armour and troops rushing to the border.

Turkish President Recep Tayyip Erdogan on Tuesday vowed to launch operations against the YPG in northern Syria.

The YPG, however, is a key US ally and now controls key urban hubs in northern Syria - including the towns of Afrin and Manbij - after a campaign against the Islamic State group.

Hemo told Kurdish news agency ANF that his forces stood "ready" to defend those towns against a Turkish assault.

"Our forces will be able to cleanse the area from Erdogan's scourges, just as we were able to cleanse it from Daesh," Hemo said, using the Arabic acronym for the Islamic State group.

"This is what the war in Afrin will be like," he said.

The US-led coalition fighting IS said on Monday it was working to create a 30,000-strong border security force in northern Syria to prevent a jihadi resurgence.

This force would be likely manned mostly by Kurdish fighters and would deploy along the Turkish frontier.

Ankara immediately objected to such a move due to allegations that the YPG is linked to the outlawed Kurdistan Workers' Party (PKK) that has waged an insurgency in Turkey since 1984.

Erdogan has long threatened an operation against the YPG's enclave in Afrin but has stepped up his threats in recent days.

On Tuesday, he warned an assault on Afrin could take place "tomorrow, (or) the day after, (or) within a short period".

"We will foil Erdogan's filthy plans. We will turn those plans to major victories for the people of the region, the Kurdish, Syrian, and Turkish people," Hemo pledged on Tuesday.

Erdogan has said the Afrin operation would be undertaken "together" with Syrian rebels, whom Ankara has backed in other operations against the YPG and IS.