Canada has imposed new rules mandating face masks for all air travelers.
All travelers must prove they have a non-medical mask or face covering, or may be denied boarding.
Only children under the age of two and some people with disabilities are exempt.
The measures take effect on Monday at midday.
"If you need to travel, wearing a face covering is an additional measure you can take to protect others around you, especially in situations where physical distancing guidelines cannot be maintained," federal transport minister Marc Garneau said.
Air passengers who display symptoms of Covid-19 will not be allowed to board aircraft.
The government says face coverings are not an alternative to physical distancing and all passengers should maintain a distance where possible.
Where it is not feasible, face coverings must be worn, such as during passenger screening.
"We’re encouraged by this announcement and believe it will help reduce risk of infection for flight attendants and the flying public," said Wesley Lesosky, president of the Canadian Union of Public Employees at Air Canada.
"Customers will be asked to lower their masks to facilitate full ID checks as required by Canadian regulations at check-in," Air Canada said.
"While onboard customers will be required to wear face coverings in accordance with the ministerial directive."
CUPE says 60 unionized employees have contracted Covid-19 in the course of their work.
People on ferries, trains or buses are ‘strongly encouraged to wear non-medical masks or face coverings as much as possible,’ Garneau added.
