Prime Minister Justin Trudeau is holding firm to his commitment to bring 25,000 refugees to Canada by the end of the year, amidst growing anxiety over security in the wake of the Paris terrorist attacks.

Speaking at the G20 summit in Turkey on Monday, Trudeau acknowledged the fear that extremists might pose as legitimate refugees, but he reiterated that "security remains a primary concern."

"We have a cabinet committee that is (working) directly on these issues to do exactly what Canadians expect Canada to do, which is welcome in refugees who are fleeing a terrible, terrible conflict in Syria, but to do so in way that keeps Canadians and their communities safe," said Trudeau.

He added that the commitment has "in no way weakened our resolve to ensure first and foremost that Canadians are kept safe."

Trudeau's comments came before Saskatchewan Premier Brad Wall released a letter to the prime minister, in which he advised him to suspend the plan over safety concerns.

Wall said in the letter that the devastating terrorist attacks in Paris last Friday, which killed 129 people and injured hundreds more, demonstrated the violence even a small number of "malevolent individuals can inflict upon a peaceful country and its citizens."

"We're saying let's get it right from a security perspective and a settlement perspective, if that means a few months, or even a longer delay, that means then it is worth it," said Wall in an appearance on CTV's Power Play.

Wall said he is concerned the security screening process could be undermined by expediting the process to bring 25,000 refugees to Canada by the end of year.

"Usually one miss out of 25,000 would be acceptable for government, for business or almost any organization. I don’t know that it is in this instance," Wall said.

Wall said that while the security screening process was perhaps "took too long" under Stephen Harper's leadership, it should not be "collapsed" into 45 days for 25,000 people.

He added that the government's goal shouldn't be driven by a "deadline" but should be focused on safety and effective resettlement.

"I just think we need to get it right with respect to security and settlement, and then be the welcoming country that Canada is. And we'd like to be the welcoming province that Saskatchewan is as well," said Wall.

Wall said that Trudeau's goal is "laudable," and Saskatchewan has increased the amount of refugees that it would be willing to accept, but "we just got to make sure we do it right."

"I don’t question the motive of the federal government -- I salute it. I know what they're trying to do, and we would like to be a part of it," said Wall.

B.C. Premier Christy Clark also said Monday that the federal government needs to ensure that the security of Canadians is the chief concern.

"They need to make sure that their processes are working, that those security checks are being done properly and then, as they can, invite those refugees to come," Clark said.

In a statement to CTV News on Monday, Immigration, Refugees and Citizenship Minister John McCallum responded to Wall's letter, saying that "effective security screening has always been paramount" in the government's refugee resettlement plan.

"The government is committed to a rigorous, balanced and compassionate response to this humanitarian crisis," said McCallum.

"This operation will be done without compromising security," he added.

Conservative interim leader Rona Ambrose also urged the Liberals to ensure that the refugees can be resettled in a "secure manner."

Speaking on CTV's Power Play Monday, Ambrose said she agreed with Wall and echoed his concerns.

"The issue is we have this election promise of a deadline 25,000 people by Christmas come hell or high water," said Ambrose.

"And I think that is a mistake. I think Canadians want this to happen but they want it to happen in a safe way."

Ambrose said that the government needs to present a "transparent" plan to Canadians in order to "reassure" them.

"Do it right, do it safely and they'll have the support of the population," she said.

However, in an appearance on CTV's Canada AM earlier Monday, Peter Showler, the former chair of Canada's Immigration and Refugee Board said that Canadians shouldn't be concerned because all of the 25,000 refugees will face a rigorous screening process.

First of all, Showler said there’s a big distinction between refugees resettling in Canada and the hundreds of thousands of displaced people streaming into Europe.

"There's a vast difference between the outpouring of 700,000 refugees pouring into Europe with no security screens, and the kind of security screens that are in place for every refugee that is resettled from the Middle East," he told Canada AM.

Concerns over the refugees fleeing the civil war in Syria are ramping up, after a Syrian passport was found lying close to the body of a suicide bomber in the Paris attacks. It has not been determined if the passport is authentic or a forgery.

However, Showler said the screening of Canadian refugees, which involves three different phases, is robust.

First, the UNHCR has already triaged the refugees and assessed those that would make ideal candidates for re-settlement, he said, noting that less than five per cent of asylum seekers make that initial cut. For these candidates, there is additional security screening so that UN officials can learn their stories, he added.

Second, Canadian visa officers conduct more screening and interviews with this group to ensure there is consistency in their cases, he said.

And finally, there is an additional security review of the candidates by Canadian security agencies, including CBSA, CSIS and the RCMP.

Showler said the entire process can be fairly quick, especially with the help of officials working on the ground in refugee camps and in countries where refugees have fled to.

"If you're living or working on the ground… you actually know a lot about refugee flows," he said, noting that experts and staff working in camps will be able to generally determine which refugees pose a security risk and which don’t.

He added that, when the Syrian civil war began four years ago, the first refugee flows out of Syria were people who were primarily secular, politically active and pro-democratic.

"They've now been in the neighbouring countries as refugees for four years," he said. "We know who those people are.

"So it's actually quite easy to identify 25,000 that fit into extremely low-risk security categories."

With files from The Canadian Press