Air Canada will temporarily lay off more than 5,100 employees as it attempts to check the impact of the coronavirus pandemic, the union representing the Canadian airline’s flight attendants said on Friday.

The Canadian Union of Public Employees (CUPE) said it was “deeply saddened” to learn that airline would temporarily lay off about 3,600 of its members at Air Canada mainline and all 1,549 of its members at Air Canada Rouge.

CUPE, which represents about 10,000 flight attendants at Air Canada and Air Canada Rouge, said the layoffs were effective until April 30 at the earliest.

Air Canada has initiated discussions with its unions to begin placing employees on temporary, off-duty status, the company told Reuters on Friday.

“Employees would be returned to active duty status when we ramp up our network schedule as conditions allow,” the company said in an emailed statement.

Earlier this week, Air Canada said it would gradually suspend the majority of its international and U.S. trans-border flights by March 31 in response to the coronavirus crisis.

Airline industry executives around the globe have called for state support as travel demand collapses at an unprecedented rate and governments impose restrictions due to the pandemic.

Air Canada has “no choice” but to cut staff, calling the move “difficult but necessary,” CBC News, which first reported the news, quoted the airline’s vice president of in-flight service as saying.

The highly contagious coronavirus has infected more than 234,000 people across the world and the death toll currently exceeds 9,700.