The CEO of Air Canada has apologized after he was criticised for not speaking French in a condolence video message he released after a collision at LaGuardia airport that killed two pilots. In a statement on Thursday, Michael Rousseau said he was deeply saddened that his inability to speak French diverted attention from the pilots' grieving families and Air Canada staff. Rousseau said he is unable to express himself adequately in French - an official language in Canada, despite taking lessons over the years. He has faced calls to resign for failing to deliver his condolences in both English and French. One of the pilots who died - Antoine Forest - is French Canadian. Prime Minister Mark Carney said Rousseau's English-only message showed a lack of compassion, while Quebec's Premier François Legault said he believed Rousseau should step down if he is unable to speak French. In a written statement, released in both English and French, Rousseau admitted that his French remains weak despite many lessons over several years. I sincerely apologize for this, but I am continuing my efforts to improve, he said. His statement did not address the calls for him to resign. Forest and the other pilot, Mackenzie Gunther, were killed when an Air Canada plane operated by Jazz Aviation collided with a fire truck on Sunday night at LaGuardia airport in New York shortly after landing. The flight had come from Montreal, Quebec. Dozens of passengers were injured, and four remain in hospital, Air Canada said on Wednesday. Shortly after the accident, Rousseau released a video statement on X expressing deepest sorrow for everyone affected. The message was delivered in English, and the video included subtitles in English and French. The statement caught the attention of Canada's parliamentary Committee on Official Languages, who summoned Rousseau to explain himself before MPs on why his message was released in English only. Rousseau lives in Montreal but is an anglophone. He has come under fire in the past for his inability to speak French, including shortly after he was appointed as CEO of Air Canada in 2021. At the time, Rousseau apologised and committed to improving his French. Air Canada began as a federal public corporation and has been private since 1988. It remains subject to Canada's Official Languages Act, however, and announcements on board planes are made in both English and French. Investigators are still working to determine the circumstances that led up to the fatal crash on Sunday evening. Authorities on Tuesday released details from the final three minutes of cockpit voice recordings and tower communications, including that controllers had cleared both the plane and a fire truck to cross the runway. The damaged airplane was towed away on Thursday, and authorities were working to reopen the runway where the collision occurred.