TORONTO -- Porter Airlines has extended its temporarily flight suspension yet again and says it hopes to restart operations at the end of March—about a year after it first halted service.

In a news release issued Monday, the Toronto-based airline said the decision was made based on the rise in COVID-19 cases as well as the lockdown measures in place across the province.

The airline, which is headquartered at Billy Bishop Airport, said it hopes to resume flights on March 29.

Porter Airlines first suspended flights on March 21, 2020 as the Canadian and United States governments banned non-essential travel between their countries. Since then, the flight suspension, which was originally slated for June 2020, has been extended numerous times.

“With the introduction of vaccines, we are more optimistic about determining a date in the near-term to reintroduce flights than at any point since the pandemic began,” said Michael Deluce, president and CEO of Porter Airlines. “More time is needed to assess the vaccine’s influence on current travel restrictions and when it is appropriate to begin operations again. We expect to establish a timeline for this to happen in the first part of 2021.”

The airline expects to provide another update later in the winter “based on the status of the pandemic and the evolution of government measures that may promote greater freedom to travel.”

The restrictions at the Canada-U.S. border are set to expire on Jan. 21, pending another extension.