Prime Minister Stephen Harper says he is now convinced Syrian President Bashar Assad has used chemical weapons against the country’s rebel forces, adding his voice to a growing chorus of international leaders slamming the Syrian leader.

Harper made the remarks in France, where he is meeting with French President Francois Hollande to discuss a Canada-Europe free trade pact.

The U.S. had announced Thursday it now has conclusive proof Assad has used chemical weapons, including the nerve-agent sarin, against opposition forces.

"We share the view of our allies, I think, based on the evidence before us, that there have been uses of chemical weapons in Syria by the regime," Harper said Friday.

"And as you know, the position of Canada on the regime is clear: we want to see Assad depart power and we want to see a regime that is representative of the entire population of Syria, which the Assad regime, in its present form, can never be."

U.S. President Barack Obama has repeatedly said the use of chemical weapons would represent a "red line" in the ongoing conflict, and on Thursday he authorized arming the Syrian rebels.

It isn't clear how the U.S. will accomplish that plan, however, and Harper said he still has concerns about sending weapons and ammunition.

"I think our concerns about the risks on both sides are shared also by our allies," Harper said.

Liberal foreign affairs critic Bob Rae said it was unlikely Canada would “get in the business of arming the rebels,” but said the West has failed to take an effective stand against Assad.

“I think the last year (in Syria) has been an incredible tragedy,” he told CTV’s Power Play. “We have not even been modestly successful in dealing with Assad.”

A United Nations report released Thursday said at least 93,000 people have now been killed in the two-year conflict.

On Friday, British Foreign Secretary William Hague said the U.K. has also concluded that Assad has used chemical weapons, including sarin gas.

France has also put forward evidence that it says proves chemical evidence has been used and has called for inspectors to be given unfettered access to sites in the war-torn country.

Turkey also issued a statement Friday saying the U.S. report corroborates its own findings on Syria. Ankara called on the international community to "unite and openly manifest its stance" against Assad.

Hague said in a statement that the crisis calls for a strong and co-ordinated response, adding that the international community must "be prepared to do more."

However, Russian President Vladimir Putin's foreign affairs adviser, Yuri Ushakov, said the evidence Russia has seen "didn't look convincing."

Security expert Eric Margolis said the situation is volatile because while the U.S. backs the rebels, Russia supports Assad.

In fact, while the U.S. has discussed arming the rebels, the Russians have approved sending missiles to the Assad regime.

"It's a claim by the U.S. government, which is fueling one side of the war in Syria. And on the other side the Russian government, which supports the government in Syria, has denounced these reports as fabrications and brought up the fake reports from the Iraq wars. We have concerns," Margolis told CTV's Canada AM.

Before travelling to Paris, Harper was in London earlier this week where he addressed British Parliament for around 30 minutes.

His speech focused mostly on economic issues but he also raised the situation in Syria.