Canada has extended economic sanctions against Syria over a continuing violent crackdown on protests against the regime of President Bashar Assad.

Foreign Affairs Minister John Baird announced the extension of measures the federal government imposed in May, saying the Assad regime "has lost all legitimacy."

The sanctions include a travel ban to those associated with the regime, freezing of assets, as well as a freeze on exports and imports to and from the country, Baird told reporters via video teleconference from Mexico.

Two new companies have been added to the list of sanctions — Syria Tel, a communications provider, and the Commercial Bank of Syria.

Minister of Foreign Affairs John Baird says the regime of President Bashar Assad has 'lost all legitimacy.' Sean Kilpatrick/Canadian Press

The measures imposed in May also included a ban on exports of items that could be used by the Syrian military, such as arms and munitions. Canada also suspended all bilateral co-operation agreements and initiatives with Syria.

The sanctions are considered largely symbolic, as Canada's exports to Syria are worth only about $60 million a year and it receives less than 10 per cent of that in imports.

Baird admitted the measures imposed by Canada, the United States and other countries haven't worked, but he said Canada and its allies are prepared to ramp up pressure.

"We're very committed to this and we'll continue to work with our allies and reach out to others to take more significant action," Baird said in a conference call from Mexico City, where he was meeting with government officials.

Baird didn't hint at what additional measures Canada might consider or when further steps could be taken. He said Canada has no immediate plans to recall its ambassador to Damascus, saying the government thinks it's useful to maintain a presence in Syria.

"I think we'll leave our ambassador in Damascus as long as we think there's a value to doing that," he said. "I think it is important that for the time being that Canada keep our ambassador there."

Syrian activists say at least 1,700 civilians have been killed in the government crackdown on protesters in the past five months.

With files from The Canadian Press