The initial program design is only for the air mode. As we start to look at the volumes of individuals who are passing across the land border, that's where the cooperation with the U.S. is so essential to an alignment between Canada's eTA and the U.S. ESTA to ensure that, once in the perimeter, security risks are absolutely minimized for crossing the 49th parallel, but to really push the risks offshore, outside continental Canada and the United States.
On November 19th, 2012. See this statement in context.