OTTAWA (REUTERS) - China said on Tuesday (June 25) it wants the Canadian government to stop allowing meat shipments to China after bogus export certificates were discovered.

The announcement comes just four days before China and the United States are due to sit down to work on settling a trade dispute that has caught Canada in the crossfire.

An investigation into Canada's export certificates has revealed as many as 188 "counterfeit" veterinary health documents and the existence of "obvious safety loopholes", the Chinese Embassy in Canada said in a statement on its website.

Canadian Agriculture Minister Marie-Claude Bibeau said in a statement that the Canadian Food and Inspection Agency (CFIA) confirmed it had found "inauthentic export certificates".

The Chinese Embassy, in its statement, said "China has taken urgent preventive measures and requested the Canadian government to suspend the issuance of certificates for meat exported to China.

"We hope the Canadian side would attach great importance to this incident, complete the investigation as soon as possible and take effective measures to ensure the safety of food exported to China in a more responsible manner," it added.

Bibeau said in her statement that the CFIA had been working closely with industry and Chinese officials on the matter.

"CFIA is investigating this technical issue and has informed appropriate law enforcement agencies. This incident is specific to export certificates to China. Export certificates to other countries are not affected," Bibeau said.

Bibeau did not say whether the CFIA would suspend the certificates, but a Canadian government source said the issue was a "technical" and not a political one, and that a "temporary suspension" may be announced.

Relations between China and Canada nosedived in December after Meng Wanzhou, the chief financial officer of Huawei Technologies Co, was detained in Vancouver on a US arrest warrant. She denies any wrongdoing and Beijing is demanding her return.

After Meng's arrest, China detained two Canadians and later formally charged them with espionage. Canada says the arrest of the two men was arbitrary. China has already blocked imports of Canadian canola seed.

In its statement on Tuesday, the Chinese Embassy did not link its call to suspend Canadian meat imports to the Meng case.

On Monday, Meng's lawyers urged Canada's justice minister to withdraw extradition proceedings against Meng, but received no immediate response.

Though the issue is not on the official agenda, Canada's justice minister, David Lametti, is due to meet US Attorney General William Barr in Washington on Wednesday.

US President Donald Trump last week told Canadian Prime Minister Justin Trudeau that he was prepared to raise the case of the two detained Canadians with Chinese President Xi Jinping, whom he is to meet with in Japan on Saturday at the Group of 20 meeting.

The United States hopes to relaunch trade talks with China.

It will be the first time Trump and Xi sit down together since trade talks between the world's two largest economies broke down in May of last year.

China bought C$310 million (S$319 million) worth of Canadian pork from January through April, making it Canada's third-largest export market by value, according to official data.

Earlier this month, Reuters reported exclusively that China planned to boost inspections of imported Canadian meats and meat products.

A Canadian Agriculture Ministry notice said the Canadian Embassy in Beijing had been told that Chinese customs agents would open all containers of Canadian meat and meat products, and that in some cases 100 per cent of the contents would be inspected.

The move to block Canadian meat imports comes at a difficult moment for Chinese pork consumers. China's sow herd is being closely watched by the global livestock market as an epidemic of incurable African swine fever has killed millions of animals in the world's most populous country, pushing up prices.