The investigation is beginning into what caused an American Airlines jet and a U.S. Army helicopter to collide midair in DC Wednesday night.

Trump said his decision will be based on whether the price of oil charged by the two trading partners is fair, although the basis of his threatened tariffs pertains to stopping illegal immigration ...

Canada has pledged to spend $1bn on border security, and has recently deployed newly leased Black Hawk patrol helicopters, extra dogs and 60 drones at the border partly in response to Trump’s demands ...