Canada remains committed to taking in 25,000 Syrian refugees but will only welcome 10,000 of them by year's end, Prime Minister Justin Trudeau's government said on Tuesday.

Trudeau had pledged to bring in the entire amount before the end of the year and had been scheduled to announce plans for doing so on Tuesday. Instead, the Liberal government said 15,000 Syrian refugees would have to wait until 2016, at the end of February.

The delay follows criticisms that Ottawa was moving too fast amid security concerns in the aftermath of deadly attacks in Paris.

"Canadians have said do this right and if it takes a little longer to do it, then take the time," Immigration Minister John McCallum told reporters.

"And so essentially this is what we are going to be doing."

The bulk of the refugees who will eventually come to Canada – about 16,000 – will be resettled in Ontario and Quebec. Many will be initially housed on Canadian military bases, but the majority is expected to end up in the Montreal and Toronto areas.

The plan will cost Canada an estimated $1.2 billion over six years, The Canadian Press reported last week.