Air Canada and the union representing 10,000 flight attendants resumed talks late Monday for the first time since a strike by the flight attendants began over the weekend.

Prime Minister Mark Carney says he’s disappointed Air Canada and the union representing its flight attendants weren’t able to reach a deal after eight months of negotiations.

The union representing more than 10,000 flight attendants says the workers plan to remain on strike even after the Canada Industrial Relations Board ordered both parties back to work by 2 p.m. ET toda...