Canada is "disappointed in the extreme" by the UN Security Council's "paralysis" after Russia and China vetoed a resolution calling for Syrian President Bashar Assad to step down.

"Today's failure by the UN Security Council to effectively deal with the crisis in Syria is yet another free pass for the illegitimate Assad regime and those backing it," Foreign Affairs Minister John Baird said in a statement issued from Tel-Aviv on Saturday.

"Canada is disappointed in the extreme."

Baird said the UN's "paralysis of power is particularly deplorable given the reported upsurge in violence overnight in Homs, which we condemn without reservation."

"Those attempting to cling to power in Syria are morally bankrupt, and their disregard for human life is surpassed only by their cynicism for doing what is just and right.

The New Democrats also weighed in, calling on the federal government to "immediately recall" Canada's ambassador from Syria but also to apply diplomatic intervention.

"We call on the Canadian government to immediately exert diplomatic pressure on China and particularly Russia in order to secure a UN resolution on the crisis," said NDP foreign affairs critic Hélène Laverdière in a written statement Saturday.

The decision by two of the Security Council's permanent members to veto the resolution comes ahead of Prime Minister Stephen Harper's second trip to China, set for next week.

Baird, who is currently in Israel as part of a Middle East trip but will be travelling to China with Harper on Monday, said Canada continues to support the efforts of Syria's neighbours and others to resolve the current crisis.

"History will judge those whose obstruction serves only to prolong this senseless violence," said Baird.

"Canada will stand with the people of Syria in their efforts to achieve for themselves a brighter future for all Syrians."

Liberal foreign affairs critic Dominic Leblanc said the Liberals "deplore" the decision by Russia and China "to stand in the way" of ending the violence in Syria.

"We must do what we can to help bring about a peaceful political transition," Leblanc said in a written statement on Saturday.

Canadians outraged at the escalating violence in Syria held protests in various cities across Canada on Saturday.

The president of the Syrian-Canadian Council, Osama Kadi, told CBC News he was "really puzzled" by Russia and China's decision to veto the deal.

The massacre in Syria "didn't move the hearts of the Chinese and Russian," he said. "We will never lose hope."

But after "almost five decades of dictatorship [in Syria], enough is enough," Kadi said outside Old City Hall in Toronto, where dozens of Syrian-Canadians gathered to protest.

About 40 demonstrators gathered at the Syrian Embassy in Ottawa Saturday morning, calling on the international community to put an end to the violence in Syria.

Overnight Friday, vandals splashed red paint on the embassy's fence and facade. The RCMP is investigating.

Syrian embassies in six other countries were also vandalized overnight.