MONTREAL -- Canada's new COVID-19 testing requirement for international travellers has caused hundreds of people to miss flights in just the first week of the program's rollout.

Under the new restrictions, all passengers flying to Canada from another country must show proof of a negative COVID-19 test taken at most 72 hours prior to departure.

Since the testing mandate went into effect on Jan. 7, WestJet has denied boarding to at least 385 guests because they did not meet the requirements, said spokeswoman Morgan Bell.

Similarly, Air Transat has denied boarding to at least 245 passengers for testing-related reasons since Jan. 7, said Debbie Cabana, a spokeswoman for the airline.

Bell said the travellers were turned away due to improper tests -- antigen or antibody tests, rather than the required PCR test common in Canada -- no test at all, or one taken more than 72 hours before departure.

"Our teams have been doing everything they can to assist guests and problem-solve in destinations across our network," Bell said. "Our WestJet Vacations team is working in destinations with our hotel partners to facilitate and arrange PCR tests whenever available to best assist our guests."

At the time the testing mandate was announced, Canada's major airlines asked the government unsuccessfully for an 11-day extension to implement the new rules, warning that they would lead to confusion for passengers.

The Canadian government has already been forced to make a temporary exception to the testing requirement in response to a shortage in supply of accepted tests in Jamaica.

The government of Jamaica said this week that it was working to increase the availability of COVID-19 PCR testing at private labs and on-site at select resorts in Ochos Rios, Montego Bay and Negril.

Hotels elsewhere in the Caribbean, such as the Bahamas' Baha Mar resort, have begun offering COVID-19 testing on-site in an effort to help international travellers comply with testing restrictions.

On Tuesday, the U.S. Centers for Disease Control and Prevention announced a measure similar to Canada's, ordering all international airline passengers to show proof of a negative COVID-19 test before boarding flights to the country.

Rocky Racco, the CEO of Toronto-based travel agency TTI Travel, said he expected the availability of testing at tourist destinations in the Caribbean to ramp up in light of the new U.S. requirement.

"Given the announcement that this is also required now by U.S. citizens, it's going to get the hoteliers' and tourist boards' fullest attention," Racco said.