Russia has said it will not allow clashes between Turkish and Syrian forces, as Turkey’s military offensive in northern Syria continues.
“This would simply be unacceptable… and therefore we will not allow it, of course,” said Moscow’s special envoy for Syria, Alexander Lavrentyev.
The withdrawal of US troops from the region, announced last week, gave Turkey a “green light”, critics say.
Russia is a key military ally of Syrian leader Bashar al-Assad.
Mr Lavrentyev, during a visit to the United Arab Emirates, described Turkey’s offensive as “unacceptable”.
He said Turkish and Syrian officials were in contact to avoid any conflict.
And Russia’s defence ministry said its forces, which have been deployed in Syria since 2015, were patrolling along the “line of contact” between Syrian and Turkish forces.
The Turkish offensive, which began last week, aims to push the Kurdish-led Syrian Democratic Forces (SDF) from the border region. Turkey considers the biggest militia in the SDF a terrorist organisation.
The Turkish government wants to create a “safe zone” in the area, where it can resettle Syrian refugees currently in Turkey.
Many of them are not Kurds and critics warn this could lead to ethnic cleansing of the local Kurdish population.
Dozens of civilians have been killed in the operation so far and at least 160,000 have fled the area, according to the United Nations (UN).
Kurdish-led forces have been a key ally of the US in the fight against the Islamic State (IS) group in Syria. They described the US withdrawal, which preceded Turkish action, as a “stab in the back”.
There are fears the destabilisation could risk a resurgence of IS, as thousands of former fighters and their relatives are being detained in northern Syria. Hundreds of IS family members are said to have already escaped from one camp.
Some aid organisations have been forced to suspend operations and evacuate international staff over security fears.
Facing immense pressure, Kurdish-led forces announced a deal on Sunday with the Syrian government for military support to help repel Turkey.
Turkish President Recep Tayyip Erdogan insists the operation will continue until his country’s “objectives have been achieved” despite the involvement of Syrian government forces.
The US has imposed sanctions on Turkish ministries and senior government officials in response to the country’s military offensive in northern Syria. -BBC