Canada has been convinced Western military action is needed against Syria after reports it used chemical weapons, says Prime Minister Stephen Harper.
However, Ottawa does not plan its own military mission.
Harper told reporters in Toronto that doing nothing in the face of what he said appeared to be an escalation in the use of chemical weapons by Syria would set "an extremely dangerous precedent."
"This is a very big risk and we do support our allies who are contemplating forceful action to deal with this," said Harper, who spoke to US President Barack Obama on Wednesday about Syria and has also talked with British Prime Minister David Cameron and French President Francois Hollande.
"That said, at the present time the government of Canada has no plans, we have no plans of our own, to have a Canadian military mission."
Canada took part in the 2011 Nato mission against the forces of then-Libyan leader Muammar Gaddafi, and for a time commanded the mission.
Because the Syrian conflict is overwhelmingly sectarian and has no ideal or obvious outcomes, Harper said his government has been "a very reluctant convert" to the need for a Western military response.
Obama speaks to White House
Meanwhile, Obama spoke by phone to German Chancellor Angela Merkel on Thursday about Syria, the White House said, as the United States seeks the broadest possible international backing to respond to a chemical weapons attack in Syria.
White House spokesperson Josh Earnest gave no details of the phone conversation.
Obama said on Wednesday that the United States has concluded that the Syrian government of President Bashar al-Assad was responsible for the August 21 attack, which killed hundreds in a Damascus suburb.
Earnest said the Obama administration is still on track to release details of an intelligence report aimed at showing why Washington is certain the Syrian government was behind the chemical weapons use.
Senior US officials are to brief congressional leaders later on Thursday in an unclassified session. – Reuters.