Prime Minister Stephen Harper has joined a chorus of Western leaders accusing Syrian President Bashar al-Assad of using chemical weapons, paving the way for an increase in military action and a possible no-fly zone.
"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," Mr. Harper said Friday in Paris after meeting with French President François Hollande. He added that Canada will now work with its allies on a response.
The United States claimed Thursday that it has proof the Assad regime used the nerve agent sarin against rebels during fighting in Aleppo, crossing a so-called "red line" in the two-year-long civil war.
Russia is disputing the claim, ratcheting tension among G8 countries before the group's meeting on Monday and Tuesday.
The urgency of the United States and its allies stems in part from the recent gains by the Syrian government in the fighting. With help from thousands of Hezbollah fighters, backed by Iran, the Syrian army has recaptured some towns and is preparing for an assault on Aleppo, Syria's biggest city, which has been held by the rebels since last year. The United Nations has estimated that 93,000 people have died in the fighting.
U.S. President Barack Obama has now authorized sending some arms to the rebels, and reports indicate he is also considering co-ordinating a limited no-fly zone with other NATO countries.
Some U.S. officials cautioned, however, that a no-fly zone would be extremely difficult to co-ordinate and would have little effect given the street-by-street fighting in Syria.
"We don't at this point believe that the U.S. has a national interest in pursuing a very intense, open-ended military engagement through a no-fly zone in Syria at this juncture," said deputy national security adviser Ben Rhodes.
The Syrian government has rejected the U.S. claims on the use of chemical weapons, saying they are based on lies.
"The White House … relied on fabricated information in order to hold the Syrian government responsible for using these weapons, despite a series of statements that confirmed that terrorist groups in Syria have chemical weapons," the Syrian Foreign Ministry said in a statement.
Russia also questions the evidence and is considering sending missiles to Syria. "I will say frankly that what was presented to us by the Americans does not look convincing," President Vladimir Putin's senior foreign policy adviser, Yuri Ushakov, told Reuters.
The escalating war in Syria is set to dominate the G8 meetings that begin Monday in Northern Ireland and could create a clash with Russia, the only G8 country backing Syria.
Mr. Obama is scheduled to meet Mr. Putin on Monday in an attempt to find a solution. But that will be much harder now that the U.S. is backing the rebels militarily and Russia continues to support Mr. al-Assad. The Russians could also veto any attempt by the U.S. to seek backing at the UN for a no-fly zone.
On Friday in Paris, Mr. Hollande called for a profound discussion on Syria at the G8. "We must exert some military pressure" on Mr. al-Assad, he said after meeting with Mr. Harper. "We must get him to understand that there is no other solution than a political solution."
British Prime Minister David Cameron welcomed the U.S. announcement and said working with moderate rebel groups was essential.
Britain and France have alleged for weeks that the Assad regime is using chemical weapons. They have also been pushing the European Union to drop its ban on supplying arms to the rebels. However, it isn't clear if either nation will begin sending weapons.
Canada and many other European countries have been leery about arming the rebels, fearing the guns and ammunition could end up in the hands of terrorist groups.
UN Secretary-General Ban Ki-moon has also expressed concern about sending more weapons into the area and questioned the U.S. claims. "The validity of any information on the alleged use of chemical weapons cannot be ensured without convincing evidence of the chain-of-custody," he said on Friday.