The case of Albertan Sarah McIver — the third Canadian recently taken into custody in China — does not appear to be related to the detention of two others, Prime Minister Justin Trudeau said Wednesday.

Trudeau made the remarks in his year-end news conference after officials from Global Affairs Canada confirmed that a third Canadian had been arrested by Chinese officials.

"The others arrested ... were accused of serious crimes, problems regarding national security, intelligence, so those cases are more serious," Trudeau said in French. "We're currently looking at them.

"We've only got the preliminary indications ... that it's not linked to a matter of national security for the Chinese. The two situations are very different. The allegations of national security problems, even objectively, are very different from a routine case or a problem with a visa or something of that nature."

Global Affairs Canada said it's providing assistance to the family but declined to provide any details about the individual, citing privacy concerns.

The Canadian Press is reporting she is from Alberta. A source told CBC News she was teaching in China when she was detained.​

Canada has faced harsh criticism from Chinese officials and media since Meng Wanzhou, a top executive with China-based telecom giant Huawei, was arrested in Vancouver earlier this month. Meng was arrested at the request of U.S. officials and released on bail pending extradition proceedings.

Not long after Meng's arrest, Chinese officials confirmed two Canadian men had been detained on national security concerns.

One of the Canadians, Michael Kovrig, served as a diplomat with GAC but was on leave to work with a non-governmental organization at the time of his arrest in China. The other man, Michael Spavor, is a businessman who arranges tours of North Korea.

Canadian officials previously identified two Canadians recently taken into Chinese custody as Michael Spavor and Michael Kovrig. (The Associated Press/International Crisis Group/The Canadian Press)

Trudeau was asked if he thought it was time for him to reach out personally to Chinese President Xi Jinping and formally request the release of Kovrig and Spavor.

"When I was in opposition ... I remember standing in the House and challenging (Prime Minister Stephen) Harper to pick up the phone and get this Canadian released. I now understand that it's always a lot more complicated than that," he said.

Trudeau said that one of the things he's learned over the past three years as prime minister, through being involved in consular cases with "a modest amount of success," is that every case is different and requires a unique approach.

"Sometimes, politicizing or amplifying the level of public discourse on this may be satisfying in the short term, but would not contribute to the outcome we all want, which is for Canadians to be safe and secure," he said.

Prime Minister Justin Trudeau spoke to reporters Wednesday in his year end interview 1:23

Erin O'Toole, the Conservative foreign affairs critic, revealed on Twitter this morning that his office contacted Foreign Affairs Minister Chrystia Freeland's office Tuesday after hearing from an MP who had been contacted by the then unnamed Canadian detainee's family.

"The family reached out to their MP, who reached out to me on how best to accelerate action. We have a contact in Freeland's office for consular issues and contacted them immediately," O'Toole told CBC News.

"We did not publicize it. Today, basic details appeared to get out, so since the family is still very worried, I put out my tweet."

Yesterday my office relayed concerns about another possible detention of a Canadian in China to Minister Freeland. We remain very concerned about these reports & continue to urge the Prime Minister to intervene personally. —@ErinOTooleMP

In an interview with CBC News, O'Toole said that the woman's family told his office that she had been working in China for months without problems when Chinese authorities suddenly reached out to question her about her visa. She was then arrested, leaving her family deeply concerned.

A source who spoke on the condition of anonymity confirmed Canadian officials did not find out about this latest detention from their Chinese counterparts.

Chinese Foreign Ministry spokesperson Hua Chunying told a media briefing on Wednesday that she had not heard of the third detention.

No change to travel advisory

The prime minister also was asked if he had given any thought to changing Canada's policy of refusing to pay ransoms for citizens abducted abroad. Trudeau said that if Canada were to start paying ransoms, Canadians abroad would be more vulnerable to abduction.

"That is a policy that Canada has taken, that many of our allies have taken, and indeed that I have brought up repeatedly at meetings like G7 meetings, to highlight how important it is for all countries to take that sort of approach," he said.

Former foreign affairs minister Peter MacKay joined Power & Politics to discuss China's detention of a third Canadian and what it means for deteriorating bilateral relations. 8:55

Trudeau also said that any decision to change Canada's travel advisory for Canadians visiting China would be left to officials and government experts who are closely monitoring the situation.

"The determination on travel advisories is (a) decision made by officials at Global Affairs Canada, who are constantly evaluating the situation facing Canadian travellers or residents in countries around the world."

Huawei and Canada's 5G

New Zealand and Australia have banned the use of Huawei products in their 5G network development, fearing Huawei could use its access to spy for the Chinese government. In August, U.S. President Donald Trump signed a bill imposing restrictions on government contracts with Huawei and ZTE, citing national security concerns.

Trudeau said that when it comes to deciding whether to allow Huawei to participate in 5G infrastructure for mobile technology in Canada, he's weighing the billions of dollars in investment against Canadians' need to "be kept safe and free from interference and cyberattacks."

As the next-generation wireless technology, 5G promises to deliver much faster internet download speeds — possibly up to 200 times faster than today's LTE networks.

Today, the Associated Press is reporting that the Czech Republic's prime minister has ordered his government office to stop using Huawei mobile phones. And British phone carrier BT said it would not use their equipment for its planned 5G mobile network.

A man walks by the Canadian Embassy in Beijing, Friday, Dec. 14, 2018. Canada is being battered by diplomatic ill winds. Global Affairs Canada says it's aware of a third Canadian citizen detained in China. (The Associated Press)

Trudeau said the decision to ban or allow Huawei in Canada should be based on facts and not recent political tensions.

"It shouldn't at all be a political decision made on how we engage, but a decision made by experts, a decision based on recommendations by our intelligence and security agencies who have an extraordinary depth of expertise," Trudeau said.