President Donald Trump, in his first Oval Office meeting with new Canadian Prime Minister Mark Carney, said there was nothing Carney could say to him Tuesday that would convince the president to reduce tariffs on Canadian goods.

The president keeps insisting that the borderline between the U.S. and Canada is “artificial.” It’s worth asking why he’s fixated on this.

The Canadian PM responds firmly as the president proposes a "wonderful marriage" of incorporating Canada into the US.