"We are in a situation where literally hundreds of thousands of Canadians and visitors to our country are being disrupted by this action," Prime Minister Mark Carney said.

Air Canada has called off its plans to resume flights on Sunday after the union representing 10,000 flight attendants announced it would defy a return-to-work order.

"Flight AI152 scheduled to operate from Zurich to Delhi on 17 August has been cancelled due to a technical reason, and subsequently due to night curfew in Zurich," Air India said in a statement.