Stephen Harper is warning Vladimir Putin that the West will stand up to Russia's fresh attempts to destabilize Ukraine.

The Prime Minister delivered a statement Monday blaming Moscow for escalating violence in eastern Ukraine, where heavily armed gunmen have been seizing government buildings in an apparently co-ordinated action.

Mr. Harper said escalating violence by pro-Russian separatists in eastern Ukraine is "patently, without any doubt whatsoever, strictly the work of Russian provacateurs sent by the Putin regime."

Story continues below advertisement

He warned Canada is ready to levy additional sanctions on Russia as the situation in eastern Ukraine comes to resemble what took place in Crimea, the Black Sea peninsula already annexed by Moscow.

Mr. Harper is calling on other world leaders to recognize how serious the crisis has become. "When a major power acts in a way that is so clearly aggressive, militaristic and imperialistic this represents a significant threat to the peace and stability of the world and it's time we all recognized the depth and the seriousness of that threat."

The Prime Minister has dispatched Foreign Affairs Minister John Baird to visit allies in Eastern Europe next week and discuss steps that can be taken to further isolate Russia. Mr. Baird will meet with officials in the Czech Republic, Slovakia, Poland, Latvia and Estonia.

Speaking at a press conference on Monday, Mr. Baird called the takeover of government buildings in a number of eastern Ukrainian cities "brazen and co-ordinated" and said compared the current situation in Ukraine with Russian intervention in Crimea before that region's referendum.

"I don't know who the Russian Federation thinks it's kidding when it tries to pretend that it has nothing to do with them," he said. "...There's no doubt for a good number of weeks, provocateurs – frankly thugs – have been crossing the border."

During Monday's meeting with ambassadors from Central and Eastern Europe, Mr. Baird and Mr. Harper met and discussed a shared desire for Europe to be "free from aggressive actors who wish to redraw its borders," he said.

The Group of Seven began preparations last month on plans for sanctions if Russia moved beyond Crimea – penalties that would target Russian industrial sectors – but the international coalition has not unveiled these yet.

Story continues below advertisement

Mr. Harper was joined for his announcement on Monday by the ambassadors of Ukraine, Poland Latvia, Estonia and Georgia, as well as the Czech charge d'affaires.

"History shows that "anybody who makes it their historical mission to turn the clock back, as Mr. Putin has determined to do – those kinds of missions always fail in the end," Mr. Harper said Monday. "We will do all in our power to make it fail."

On Sunday, the Canadian government said "there are disconcerting parallels between what is now happening in eastern Ukraine and the events leading to Russia's illegal, illegitimate invasion of Crimea. Russia must step back and take real steps to de-escalate the situation."

Ottawa added: "Canada and its allies are prepared to take additional steps that will further isolate Russia economically and politically."