Russia on Thursday warned Turkey against deploying surface-to-air Patriot missiles to protect its troubled border with Syria, saying it should instead use its influence to help broker peace in the war-torn country.

"The militarisation of the Syrian-Turkish border is of course a worrying sign," foreign ministry spokesman Alexander Lukashevich told a briefing.

Turkey, he said, should use its influence with the Syrian opposition to help the two sides in the civil war start a dialogue as soon as possible instead of "flexing muscles and placing the situation on a dangerous course."

"Such steps clearly do not add optimism from the point of view of a political settlement," he told reporters regarding the possible missile placement.

Lukashevich spoke after Turkey had turned to NATO to request the deployment of Patriot missiles, something alliance chief Anders Fogh Rasmussen said Wednesday "would augment Turkey's air defence capabilities to defend the population and territory of Turkey."

He added it would contribute to the de-escalation of the crisis along NATO's southeastern border, where Turkey has frequently retaliated for Syrian mortar fire into Turkish territory.

Rasmussen said NATO would consider the request for Patriots "without delay." The approval is expected in coming days, diplomatic sources have said.

Turkey's Foreign Minister Ahmet Davutoglu said in Ankara this week that the surface-to-air missiles were "a precautionary measure, for defence in particular."