Russian President Vladimir Putin on Friday ordered his forces in Syria to take tough action against any threats, speaking two weeks after Turkey shot down a Russian warplane in the war-torn country.

"I order you to act as tough as possible," he told a defense meeting.

"Any targets threatening the Russian grouping or our land infrastructure should be immediately destroyed."

"I would like to warn those who would once again try to organize some sort of provocations against our servicemen," he said in a thinly veiled threat to Ankara.

Last month, Turkey shot down a Russian warplane on the Syrian border, claiming it violated Turkish airspace.

After the downing of the jet, which led to the deaths of a pilot and another serviceman who tried to rescue him, Russia introduced economic sanctions against Turkey and beefed up its firepower at its airbase in Syria.

Putin's call for a tougher military response is also likely to cause concern among monitors who have repeatedly accused Russia of conducting an indiscriminate bombing campaign in Syria.

He also claimed Russia was backing the Free Syrian Army (FSA) with arms in joint ­operations with ­government forces.

"Right now several of its units numbering more than 5,000 people as well as regular forces are conducting an ­offensive against terrorists in the provinces of Homs, Hama, Aleppo and Raqa," Putin said.

"We are supporting them (the FSA) from the air as well as the Syrian army, assisting them with weapons, munition and materiel."

Syria's rebel forces have regularly rejected the possibility of cooperating with the government or Russia and there has been no evidence of such cooperation.

When Russia said in October it was ready to provide air support for Western-backed moderate rebels battling both jihadists and Syrian President Bashar al-Assad, those groups ridiculed Moscow, urging it to stop bombing them first.

Russia has been carrying out airstrikes in the war-­ravaged nation at Assad's ­request since the end of September, while a US-led coalition is conducting its own campaign targeting Islamic State (IS).

Earlier this week, Russia said it hit IS targets with missiles fired from a submarine in the Mediterranean for the first time since launching the campaign.