Canadian diplomats received consular access on Sunday to the second of two men detained by China over the past week, Canada's foreign ministry said in a statement that gave few details.

John McCallum, Canada's ambassador to Beijing, met Michael Spavor, the statement said. Spavor and Michael Kovrig were both picked up after Canada arrested a senior Chinese executive on a U.S. extradition request.

Canadian Prime Minister Justin Trudeau — who said on Friday the detentions were unacceptable — told CTV his government was taking the situation very seriously.

"We have engaged with the Chinese officials to determine what exactly conditions are they being detained under? Why are they being detained?" he said in an interview aired on Sunday.

McCallum met Kovrig for the first time on Friday.

U.S. Secretary of State Mike Pompeo said on Friday that China should free the two men.

Spavor, a businessman, and Kovrig, a former diplomat, were detained after Canadian police arrested Huawei Technologies Chief Financial Officer, Meng Wanzhou, on Dec 1. U.S. prosecutors accuse Meng of misleading multinational banks about Iran-linked transactions, putting the banks at risk of violating U.S. sanctions.

Meng, who is the daughter of Huawei's founder, has said she is innocent. China has demanded Canada free Meng and threatened unspecified consequences if it does not.

On Monday, influential state-back newspaper the Global Times said in an editorial that an escalation in the spat with Canada could be coming.

"In the struggle with Canada, China needs to prepare for the possibility of conflict escalation," it said.

"Beijing must take the contest seriously and maximize the support of international public opinion, leaving Western media no smear to slander its counterattacks as 'degradation of China's opening-up.'"

Trudeau told CTV that Canada would continue trying to build up trading ties with China.

"We need to do so in a way that is true to our values and stands up for Canadians' interests, and getting that balance right is complex. (It) has been made more difficult by recent trends," he said.