Canadian airlines have canceled over 100 flights at Toronto\'s Pearson International Airport on Sunday as Hurricane Irene that ravaged through the U.S. East Coast is approaching the country, the Toronto Star newspaper reported. The affected flights include ones arriving in and departing from New York, Washington, Philadelphia and Boston. Several flights in airports in Ottawa, Montreal and Halifax were also canceled due to Irene, which hit the U.S. East Coast on Saturday. Irene has been downgraded from the hurricane to a tropical storm and may later be further downgraded to a post-tropical storm. \"I want people to understand that this is not over,\" U.S. President Barack Obama said Sunday evening from Washington. \"The recovery effort will last for weeks or longer.\" Millions of homes and businesses have been blacked out and about 20 people died as Irene pounded through the U.S. states of North Carolina, Virginia, Maryland, Delaware and Pennsylvania, as well as New York City and Washington, D.C.