Canada has introduced a new entry requirement, known as Electronic Travel Authorization (eTA), for visa-exempt foreign nationals travelling to Canada by air. Exceptions include U.S. citizens and travelers with a valid visa. Entry requirements for other methods of travel (land, sea) have not changed. Starting August 1, 2015, eligible travelers can apply online for an eTA. On March 15, 2016, this entry requirement will become mandatory and travelers will need an eTA before they can board a flight to Canada. Go to Government of Canada, ‘Visit Canada’ page here.