Canada's liberal PM Justin Trudeau comes out against Syria intervention

Canada's prime minister has said the Canadian military will not take part in expected US action against Syria in the wake of a suspected chemical attack against civilians.

Justin Trudeau made the comments to state-run Radio-Canada on Wednesday, stressing that he was opposed to getting involved in a conflict that could escalate.

"We are not looking to be present in Syria," Trudeau said during the French-language interview.

"Is Canadian involvement in a conflict that could degenerate further conceivable?" he asked.

Trudeau stressed that his government has been involved in delivering humanitarian assistance and working through diplomatic and political channels to resolve the conflict in Syria.

A suspected regime chemical attack in the rebel-held Syrian town of Douma last weekend killed at least 40 people and injured 1,000 people.

The prime minister's comments come amid speculation that the US, France and Britain could soon launch a military strike against the Syrian regime.

US President Donald Trump tweeted on Wednesday that missiles "will be coming."

British Prime Minister Theresa May summoned her Cabinet back from vacation on Thursday to discuss military action against Syria, while French warplanes thought to be preparing to join the US-led operations.

The United Nations has warned world powers against letting the crisis "spiralling out of control".

With punitive US military action seemingly imminent, Damascus's ally Russia has scrambled to deflect blame from Syria's Bashar al-Assad, while regime forces have evacuated key defence buildings in Damascus.

If the US action follows the pattern of a previous punitive strike on Syria last year, it will begin with a salvo of cruise missiles fired from US warships in the Mediterranean.