Conservative Leader Andrew Scheer said Wednesday he has serious concerns about the World Health Organization (WHO) and its relationship with the communist regime in China.

Scheer also said he has reservations about the agency's track record during the pandemic, citing its initial claim that the virus did not spread easily between people, and its warning against closing borders to member states like China, as questionable advice given what we know now about the virus.

"We've got serious concerns about the accuracy of the information coming out of the WHO and it's incumbent upon this government to explain why they have based so many of their decisions on the WHO," Scheer said.

The WHO also advised against the use of non-medical masks by the general population, guidance that Canadian public health officials repeated for weeks — until they changed their position last week.

Watch: Andrew Scheer says he has 'serious concerns' about the WHO

Conservative Leader Andrew Scheer says he has "serious concerns" about the WHO's pandemic performance and its relationship with the communist regime in China. 2:29

Dr. Theresa Tam, the federal chief public health officer, now says wearing a mask could help slow the spread of COVID-19 by pre-symptomatic and asymptomatic people. She has said she'll wear a mask in public when social distancing isn't possible. Tam has served as an international expert on a number of WHO committees.

Based in part on WHO guidelines, the Canadian government also avoided closing its border to inbound foreign nationals for weeks — until an abrupt about-face in mid-March when it became clear such an action was crucial to stopping the influx of cases from abroad.

While caseloads spiked worldwide, the WHO waited until March 11 to declare COVID-19 a global pandemic.

"We've seen examples of how the communist, autocratic, human rights-abusing government of China has had an inordinate effect on the WHO. There's evidence of suppressing information, not being open and transparent about the number of cases. Those are very concerning," Scheer said.

The Associated Press reported Wednesday that the Chinese regime suppressed evidence of the virus's transmissibility for six days in early January before going to the WHO to brief the agency on the extent of the COVID-19 outbreak.

The current director-general of the WHO, Tedros Adhanom, visited China in January and praised the country's leadership for "setting a new standard for outbreak response."

The AP report comes a day after U.S. President Donald Trump announced his government would suspend its contributions to the WHO's budget. The U.S. is responsible for 15 per cent of the organization's funding, or some $400 million a year.

Trump said the WHO is complicit in the death of thousands because of its questionable response to the virus to this point.

Tedros Adhanom Ghebreyesus, director general of the World Health Organization, addresses a news conference about COVID-19 in Geneva, Switzerland. (Salvatore Di Nolfi/AP)

Health Minister Patty Hajdu said Wednesday that the federal government still has confidence in the WHO.

"Canada values the work of the World Health Organization and we continue to commit to contribute towards the work of the organization. It is a very valuable tool," she said.

Scheer said he was troubled when Bruce Aylward, a Canadian epidemiologist who headed a WHO mission in China earlier this year, was dropped from the witness list for a House of Commons health committee meeting on Tuesday.

Aylward abruptly cancelled his appearance and did not reschedule.

Watch: Health Minister Patty Hajdu on the WHO

Health Minister Patty Hajdu was asked what she makes of President Donald Trump's comments on WHO and his decision to withdraw U.S. funding from the organization. 1:04

Matt Jeneroux, the Conservative health critic, said Aylward's actions were "unacceptable" and asked "who's really making the decisions" at the Switzerland-based organization.

The health committee voted Wednesday to summon Aylward to appear before that body before May 1.

"The WHO has backtracked on every position they have taken, meaning the Canadian government has backtracked as well," Jeneroux said in a media statement.

"There are many important questions Canadians have for the WHO about its advice in the past three months and what it has planned for the future. While it avoids questions, cases are growing and Canadians are more uneasy than ever."

When asked about the WHO's record during a pandemic that has now infected some two million people worldwide, Prime Minister Justin Trudeau said Canada would continue to work with the United Nations-affiliated agency because this virus demands a global, coordinated response.

Watch: Prime Minister Justin Trudeau on the WHO's pandemic role

Prime Minister Justin Trudeau was asked by reporters about WHO funding — but drew a blank on how much Canada is contributing this year. 2:44

"I think there are, obviously, reflections that we have to have going forward. We have to make sure that we are doing everything we can to keep Canadians safe. That is our focus right now. What can we do now? What do we need to do in the coming weeks?" Trudeau said.

"How do we lean on experts in international institutions and in partner countries around the world who are making recommendations alongside our domestic experts on what we need to do now?"

Trudeau said there will be "plenty of time to reflect on challenges" in the future.

Watch: Scheer reiterates concerns about Canada's 'reliance' on China and the WHO on Thursday