Canada’s prime minister, Stephen Harper, has promised to do more to help Syrian refugees if his Tories are re-elected.

Harper has come under fire for not welcoming more Syrians fleeing their country’s deadly conflict. Canada agreed to resettle 20,000 refugees, but, as of late July, had welcomed only 1,002, according to government figures.

The prime minister told reporters ahead of the 19 October election that a re-elected Conservative government would “do more” but insisted increasing quotas alone would not resolve the crisis.

“But … as we are doing more, we can’t lose sight of the fact that refugee resettlement alone cannot in any part of the world solve this problem,” he added.

“As long as we have organizations like Isis or the so-called Islamic State, creating literally millions of refugees and threatening to slaughter people all over the world, there is no solution to that through refugee policy,” Harper said.

“We have to take a firm and military stance against Isis and that’s what we’re doing.”

Canada joined the US-led coalition fighting the extremist group in November 2014, adding airstrikes on targets in Syria the following year.

Hundreds of thousands of Syrians have flocked to Europe, seeking to escape a conflict that has been raging since March 2011.

The New Democratic party leader, Thomas Mulcair, said: “This is an international crisis and it’s a humanitarian crisis on a scale not witnessed since the second world war and we’ve got to step up to the plate.”

The Liberal leader, Justin Trudeau, has pledged to end Canada’s bombing mission in the region.

On Wednesday, he chastised the Tories for missing their own refugee resettlement targets, and vowed to top those figures if his party is elected.

“Unfortunately, the Conservative government despite its promises hasn’t once lived up to even its meagre commitments in terms of accepting refugees from Syria and elsewhere,” Trudeau said.