Turkish President Recep Tayyip Erdogan on Sunday held talks with Russian Defence Minister Sergei Shoigu in Istanbul as tension soared on the Syrian border between Turkish troops and a Kurdish militia.

Turkey and Russia were long at loggerheads over the Syrian conflict, with Ankara seeking the ouster of President Bashar al-Assad and Moscow remaining his chief international ally.

But cooperation had tightened markedly since last year, with the two countries jointly sponsoring peace talks in the Kazakh capital Astana.

Sunday's meeting took place at Istanbul's Tarabya Palace by the Bosphorus, the presidency said, with images showing Turkey's top general Hulusi Akar and spy chief Hakan Fidan were also in attendance.

Last August, Turkey launched its Euphrates Shield cross-border operation aimed at clearing the border zone in northern Syria of both Kurdish militia fighters and jihadists.

The operation was wound up in March but Erdogan has not excluded a new cross-border offensive should the need arise.

Turkish troops and Syrian Kurdish People's Protection Units (YPG) have repeatedly exchanged cross-border fire in recent days and there is speculation Ankara may be planning an assault on the group in Afrin.

Ankara considers the YPG a terrorist group and the Syrian branch of the Kurdistan Workers' Party (PKK) which has waged an insurgency inside Turkey since 1984.

But Washington is arming the YPG and the group is heavily involved in the US-backed operation to oust Islamic State (IS) jihadists from their stronghold of Raqa.

The Sabah daily said Sunday that pro-Ankara Syrian rebels were on standby for an operation against the YPG and Russia could ensure security in the air.

Asked about the possibility of an operation around Afrin, presidential spokesman Ibrahim Kalin said Saturday: "We take all measures to protect our borders and national security."

He said the Turkey would "instantly" hit back against any threat from Syria, be it from IS, the PKK or the YPG.

Source: AFP