Vladimir Putin has warned that the Russian military will “immediately destroy” any targets threatening its forces in Syria.
At a meeting with top brass, the president said the Russian military base in Syria has been beefed up with additional aircraft and air defence weapons.
The build-up followed the downing of a Russian warplane by a Turkish fighter jet at the Syrian border on November 24.
Without naming Turkey, Mr Putin warned anyone against “further provocations”, saying the military will respond in “the toughest way”.
Mr Putin said the mission in Syria is aimed at protecting Russia from extremists based there.
He said the extremists pose a “clear threat” to Russia, and fending off that threat is the main goal of the air campaign Moscow launched on September 30.
Defence minister Sergei Shoigu said Russian warplanes have flown 4,000 combat sorties in Syria since the launch of air strikes, destroying 8,000 “terrorist” targets.
He added that Russia helped restore a tank repair factory in the Syrian province of Homs, which he said is now working at full scale.
Mr Putin said the Russian military action had helped change the situation in Syria, supporting the Syrian army offensive, and helping some units of the opposition Free Syrian Army to fight “terrorists”, providing air cover and supplying them with weapons.
Mr Shoigu said the military has received 35 new intercontinental ballistic missiles this year as part of an ambitious arms modernisation effort.
He said the military has also received 243 aircraft, 90 air defence systems, 1,172 tanks and other armoured vehicles, two new nuclear-powered submarines, two general-purpose submarines and eight surface warships.
Mr Shoigu said a steady series of military exercises has helped improve skills and contributed to a successful performance of Russian pilots in Syria.
Meanwhile, Turkey’s foreign minister said his country is refraining from responding to Russian efforts to hit back over the warplane, but added that Turkey’s patience is not without limits.
Mevlut Cavusoglu said Ankara wants to overcome tensions but Moscow is using “every opportunity” to hit back.
The downing of the jet has brought previously warm ties between Turkey and Russia to a post-Cold War low. Russia slapped economic sanctions on Turkey and recently took the issue of Turkey’s deployment of troops in Iraq to the United Nations Security Council.
Mr Cavusoglu told NTV television: “If we are not responding to all that they have done until now, it is not because we are afraid or because any psychology of guilt.”