Vladimir Putin told Russian security chiefs to do everything necessary to prevent "coloured revolutions" such as those seen in Ukraine from reaching Russia as it was announced that nearly 1,000 people have died there since the September truce.
Russian officials also accused the United States of "destabilising" the situation in Ukraine on Thursday by considering supplying Kiev with weapons.
"In the modern world extremism is being used as a geopolitical instrument and for remaking spheres of influence. We see what tragic consequences the wave of so-called colour revolutions led to," Mr Putin said at a meeting of Russia's Security Council.
"For us this is a lesson and a warning. We should do everything necessary so that nothing similar ever happens in Russia," he added.
The "coloured revolutions" were a series of popular uprisings that toppled governments in former Soviet republics including Ukraine, Georgia, and Kyrgyzstan in the 2000s. A similar uprising overthrew Viktor Yanukovych, the pro-Russian president of Ukraine, in February.
The resulting war has killed more than 4,000 people to date and plunged relations between Russia and the West to their lowest point since the end of the Cold War.
Nearly 1000 people have been killed in the fighting there since a ceasefire came into effect in September, equivalent to 13 people per day, the United Nations said on Thursday.
Zeid Ra'ad Al Hussein, the UN high commissioner for human rights, said in a statement that the total death toll had reached at least 4,317 by Tuesday.
"The list of victims keeps growing. Civilians, including women, children, minorities and a range of vulnerable individuals and groups continue to suffer the consequences of the political stalemate in Ukraine," Mr Al Hussein said in a statement.
The latest United Nations report on the conflict came as international monitors in the region said they had been shot at by armed men.
A team of monitors from the Organisation for Security and Cooperation in Europe were shot at twice by a uniformed man in the back of a lorry as they patrolled an area near the line separating government and separatist held territory on Wednesday, the OSCE said.
No one was hurt in the incident near Mariinka, a government-controlled town about 10 miles west of the rebel stronghold of Donetsk.
A senior OSCE official called the prospect for peace "bleak," but rejected suggestions that the ceasefire had entirely collapsed, calling the accord "the door on the road to peace." "Yes, it has been broken many times but it is the only agreement in place which has any restraining power on the use of force," Heidi Tagliavini, the OSCE envoy to a trilateral contact group including Ukraine and Russia, said.
Russia has accused Ukraine and the West of fuelling the conflict.
Vadimir Chizhov, Russia's permanent ambassador the EU, said there was "growing concern amongst the population of eastern Ukraine, and also Russia," about Ukraine troop build up near the front line separating government and separatist forces.
In a separate statement, deputy foreign minister Alexander Lukashevich said any delivery of US military hardware to Ukraine would be a "destabilising factor". Mr Lukashevich was responding to reports that a US official had suggested supplying arms to Ukraine.
Joe Biden, the US vice president, arrived in Kiev late on Thursday to meet Ukrainian officials and express support for the new government.
Western countries, including the UK, have previously supplied Ukraine with non-lethal assistance in the form of body armour, rations, and medical kits, but have so far stopped short of providing weapons.
Ukraine and Nato have repeatedly warned in recent weeks that separatists backed by Russian regular troops are massing on the rebel side of the lines inside the self-proclaimed "people's republics" of Luhansk and Donetsk.
The build up of troops has led to fears of a return to full scale offensive operations.