Syrian Kurds won't attend Russia's Sochi congress: Kurdish official

Donald Trump on Wednesday chewed out Turkish president Recep Tayyip Erdogan in a phone call, just days after Turkey bombed US -backed Kurdish fighters in Syria.

U.S. President Donald Trump spoke by phone with his Turkish counterpart Recep Tayyip Erdogan on Wednesday, urging his North Atlantic Treaty Organisation ally to limit its military actions in northern Syria, according to a White House statement.

According to two major Turkish dailies, Hurriyet Daily News (Ankara) and Daily Sabah (Istanbul), the official sources said, "Trump did not express concern over a so-called escalating violence as a result of Turkey's anti-terror operation in Afrin".

This would bring Turkish troops and allied forces closer to Washington-backed Kurdish fighters and USA forces who are based near Manbij, but not in or around Afrin.

For the past four days, Turkish troops and allied Arab Islamist fighters have been battling their way into Syria's Afrin canton, which is defended by the American-backed Kurdish YPG militia.

U.S. Secretary of State Rex Tillerson urged Turkey to exercise restraint, and ensure that its military operations in Afrin are limited in order to avoid civilian casualties.

The paper said that the YPG has reportedly welcomed the entry of the Syrian army to Afrin under a deal with the Syrian government, a claim that hasn't been publicly declared by the YPG.

Presidential spokesman Ibrahim Kalin told CNN Turk on Tuesday that the prerequisite for Turkey to cooperate with the United States in Syria is that Washington ends its support to the YPG and takes back the arms it provided to the group.

In their Wednesday call, Erdogan and Trump also welcomed the return of more than 100,000 refugees to Syria after the defeat of Islamic State forces.

"If the United States doesn't stop this, we will stop it", he said.

"The US president touched upon the necessity of limiting the duration of Operation Olive Branch and, keeping in mind the presence of a small number of US troops in Manbij, the need to prevent a hot conflict in the area", the Turkish official said.

Sabri Hanan, an Afrin resident, said that civilians were continuing to join the Kurdish forces on the front lines in "large numbers".

Some Turkish officials have said the main aim is the creation of a 30-kilometer (20-mile) deep "secure zone" in Afrin, which Turkey says is essential for its security. "We would appreciate it and we would urge them to limit the incursion as much as possible".

Bossert meanwhile said it would be a "terrible outcome" if Turkish troops clashed with "the proxy forces that we have all been relying on to defeat ISIS, especially if there are USA advisers in the region".

Turkey accuses the YPG (People's Protection Units) of having links to the banned Kurdistan Workers' Party (PKK) group within its own borders.

USA -backed Syrian fighters in the Manbij area have deployed to frontlines to confront any Turkish assault and are in contact with the US -led coalition over defending the town, their spokesman Sharfan Darwish said on Wednesday.

Turkish jets could not operate over Syria's northwest without both Russian Federation and Syria agreeing not to use their powerful anti-aircraft missile systems against them.

A senior USA official said that as of Tuesday the Turks had not been ready to engage in detail on such a proposal.