The Cuban government is criticizing Canada's decision on Wednesday to halve its embassy staff after a 14th Canadian fell ill to an unexplained illness in Havana.

Josefina Vidal, Cuba's ambassador to Canada, says that reducing embassy personnel in Havana will do nothing to help find the cause of a mysterious ailment that has affected Canadian and American diplomats.

Canada and Cuba have been co-operating to find the cause to the mysterious set of circumstances, but the Americans have criticized the Cubans over the matter, walking back major improvements in their strained relations that had begun under former U.S. president Barack Obama.

Vidal said that "Canada's decision made public today is incomprehensible."

She said the decision will "not help find answers to the health symptoms reported by Canadian diplomats, and which will have an impact on the relations."

Canada's decision comes after a new report concerning a diplomat who arrived in Cuba in the summer who was found to have symptoms on Dec. 29 of the mysterious illness that causes problems including nausea, dizziness, headaches and trouble concentrating.

The fact that a recently arrived diplomat reported symptoms underscores the likelihood that the undiagnosed ailment that has afflicted Canadian and American diplomats is still a threat.

Canadian government officials, speaking on the condition of anonymity, said Wednesday that Global Affairs Canada will consider halving its diplomatic presence in the Cuban capital, potentially reducing its representation by eight people from the current 16 serving in the Havana embassy.

The remaining diplomats will deliver full consular services but other programs will have to be adjusted in the coming weeks.

'Frustrating'

The move follows the downsizing in April that determined that diplomats posted to Cuba would not be accompanied by families and dependents due to the uncertainty.

In November, a 13th Canadian reported symptoms, sparking a new round of medical testing that turned up the next case in December. The November case was the first to be reported since October 2017, officials said.

"These recent confirmed cases demonstrate that these incidents are still ongoing," said one official.

The RCMP is leading an investigation into the cause of the ailments that have affected both serving diplomats and family members and have also struck several American diplomats in Havana.

Canadian authorities say they are getting good co-operation from the Cuban government, which is also frustrated by the incidents.

"Overall, we have a multifaceted relationship with Cuba, which is very positive and continues," said another official.

'Crickets'

The Cuban envoy said that is not how her government sees it.

"This behaviour favours those who in the United States use this issue to attack and denigrate Cuba," said Vidal.

The Cuban government has said the Trump administration is using the issue to roll back new measures instituted by the Obama administration to re-engage with its Caribbean island neighbour after five decades of tensions dating back to the height of the Cold War.

The U.S. withdrew most of its non-essential diplomatic staff in September 2017 but Canada did not.

Officials said the government made assessments based on "evidence" in taking its various decisions to gradually reduce Canada's diplomatic footprint in Cuba, which hosts an average of one million sun-seeking Canadian tourists annually.

"There is no evidence that Canadian travellers to Cuba are at risk," Global Affairs Canada said Wednesday, adding that travellers should continue to consult the government's travel advisories.

Canadian officials say they are co-operating fully with their American counterparts but refused to say whether the fact the Cubans and Americans aren't getting along is having an effect on the search for the mysterious cause.

Speculation has focused on some kind of acoustic or microwave assault, unknown contaminants and even chirping crickets. Officials have all but ruled out environmental factors — such as toxins in the air, soil or water — and no longer suspect a sonic attack is to blame.