Foreign Affairs Minister John Baird used some of the toughest language yet, describing Russia's incursion as "old Soviet-style" aggression and saying President Vladimir Putin's attempts to justify it are "absurd and ridiculous."
But, while he spoke of the possibility of further sanctions, including expelling Russia's ambassador to Canada, he ruled out a military response to the crisis by western nations.
"I don't think there's anyone talking about western military intervention, none of our friends or allies," Baird said Sunday in an interview with Global's West Block.
"What we are doing is working together to say in no uncertain terms that this is completely unacceptable and to condemn (it) in the strongest language possible."
That message was echoed in a statement issued late Sunday by members of the G7, as well as the presidents of the European Council and the European Commission.
They called Russia's actions a "clear violation of the sovereignty and territorial integrity of Ukraine, in contravention of Russia’s obligations under the UN Charter and its 1997 basing agreement with Ukraine."
All vowed to temporarily boycott preparatory meetings of ministers and officials for the G8 summit, which is supposed to be held in June in Sochi, where the Winter Olympic games just ended. Canada had already announced its decision to pull out of the meetings on Saturday.
Baird's own language Sunday was harsh. He dismissed Russian arguments that it needs to protect its Black Sea naval fleet, which is based in Sevastopol on Ukraine's Crimean Peninsula, and the Russian-speaking population in that region.
"There is absolutely no justification whatsoever," Baird said.
"The claims that President Putin puts forward are absurd and ridiculous. He has no right to invade another country, a neighbouring country that's struggling for freedom and democracy.
"The excuses and the rhetoric that's coming out of Moscow are unacceptable. No one is buying them in the western world and they make President Putin look ridiculous."
On Saturday, Prime Minister Stephen Harper announced that Canada is withdrawing its ambassador from Russia.
"Next month there's a G8 foreign ministers' meeting and if (Putin) continues with this provocative action, there's certainly no way I or Canada would want to have anything to do with Russian world leadership," Baird said.
Whether the G8 leaders' summit itself goes ahead will be up to Putin, he added, stressing that Russia must be made to realize that its actions "will have a major effect on Russia's relationship, not just with Canada but the entire free and democratic world."
Baird was returning Saturday from Kyiv, where he led a Canadian government delegation to show support for Ukraine's new pro-western government.
In his absence, he said his deputy minister called in Russia's ambassador to Canada, Georgiy Mamedov, and reamed him out "in the strongest terms certainly in my time at Foreign Affairs."
He did not rule out expelling the ambassador.
"We'll obviously be revisiting this on an hour by hour basis," he said, adding that Canada wants to act "in unison" with its allies.
At a later news conference in Toronto, Baird did not rule out further sanctions, including freezing Russian assets, trade and investment penalties and a ban on visas.
"It's certainly something we'll consider in the next few days."
NDP Leader Tom Mulcair, who was briefed by Harper on the situation Saturday, threw his whole-hearted support behind the government's response to the crisis.
"I think that Canada's been getting it right in terms of our very strong reaction to what the Russians have done," he told a news conference in Toronto.
"It's absolutely unacceptable to be violating Ukraine's sovereignty in this way and the prime minister and I have spoken and he has my full support with the steps that have been taken so far."
However, two of Canada's most distinguished former diplomats dismissed the Harper government's response thus far as "bluster" and meaningless "gestures."
Jeremy Kinsman, former ambassadors to Russia, Britain, Italy and the European Union, and Paul Heinbecker, former ambassador to the United Nations, were particularly critical of the government's decision to withdraw Canada's ambassador to Russia and to threaten Mamedov's expulsion. They said a crisis like this is precisely when high-level diplomatic contact should be maintained, not cut off.
In an interview, Mulcair said it would be a mistake to expel Mamedov at this point.
"To the extent that we have to keep some channel of communication open, I think that it would be a mistake to consider expelling him at this stage with what's now happening," he told The Canadian Press.
Baird significantly turned down the volume on his own rhetoric at the later news conference, adopting a more diplomatic tone. For instance, rather than repeat his assertion that Putin's explanations for the invasion are absurd and ridiculous, he said: "We just disagree in the strongest of terms with the justifications, with the so-called justifications that are being put forward."
He said Canada is not currently considering expelling the Russian ambassador, stressing the need "to be careful that we take measured responses that actually will support the Ukrainian people." And he added: "Our first goal is to de-escalate the situation."
On Saturday, Harper spoke with U.S. President Barack Obama and the two agreed to "co-ordinate closely" their response to Russia's invasion of Ukraine. Harper has also spoken to German Chancellor Angela Merkel and British Prime Minister David Cameron.
On Sunday, Harper spoke to Paul Grod, president of the Ukrainian Canadian Congress, who is in Ukraine.
A senior government official said Harper reiterated the need for Russian troops to withdraw and emphasized that Canada recognizes the legitimacy of the transitional Ukrainian government, installed after massive pro-democracy protests forced pro-Moscow President Viktor Yanukovych to flee. Grod thanked the prime minister for Canada's leadership, the official said.
Russian Prime Minister Dimitry Medvedev, however, called the new government illegitimate and warned that continued "lawlessness" in Ukraine will end in revolution and bloodshed.
In his statement Saturday, Harper said Canada also supports the United Nations sending international monitors to Ukraine and is involved in multilateral talks to put together a financial aid package for Ukraine, which is on the brink of bankruptcy.
Employment Minister Jason Kenney told CTV's Question Period on Sunday that Canada has indicated "support in principle" for an International Monetary Fund aid package. He said "basic economic stability for Ukraine at this sensitive moment is critically important."
Despite the sanctions, Canada does not intend to withdraw its athletes from the Paralympics, set for March 7-16 in Sochi.
"We don't want the athletes to pay the price for this," Baird told Global.
However, he said no government representative will attend the games "to somehow glorify Russia's time in the spotlight."
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