TORONTO -- Porter Airlines will be extending its flight suspension by another four weeks due to the ongoing COVID-19 pandemic.

The airline, which is headquartered at Billy Bishop Airport in Toronto, temporarily haltered operations on March 21 as the country started to enact travel restrictions and public health measures to stop the spread of the deadly virus.

Flights were originally slated to resume on June 1.

In a news release issued on Monday, Porter said that flights will no longer begin operating until June 29.

"Our initial restart date of June 1 was something we believed was reasonable at the time," Michael Deluce, president and CEO of Porter Airlines, said in a statement.

“While there are many promising signs about how COVID-19 is being contained, it is also clear that border restrictions, government-imposed stay-at-home orders and bans on non-essential travel will remain in place for many regions through much of May and into June. This makes it difficult for people to travel, so Porter will continue aligning its approach with the public health response."

Deluce added that while the company is “eager to restart operations,” additional measures will need to be introduced before restarting fights.

We're extending our temporary suspension of flights until June 29. With many border restrictions, government-imposed stay-at-home orders & bans on non-essential travel expected to remain in place for a number of weeks, we're aligning our approach with public health guidance. — Porter Airlines (@porterairlines) April 27, 2020

Porter has said they are waiving change and cancellation fees on all tickets booked by June 29.

Last week, Air Canada announced they were suspending flights to the United States as of April 26 due to an extension of border restrictions. Numerous airlines, including Air Canada, Sunwing Airlines Ltd. and WestJet announced last month they would be suspended most international flights until June.