NORAD officials said the public may see and hear military aircraft flying close to other aircraft as they practice a 'simulated interception.'

In written remarks to the U.S. Senate committee on armed services, U.S. Gen. Terrence O'Shaughnessy said Russia has been steadily expanding its military presence in the North by upgrading its long-range bombers and developing new warships capable of carrying cruise missiles.

The two TU-160 Blackjack bombers crossed the North Pole and approached Canada from western Russia, but remained in international airspace before departing, according to Norad.

Canada has been on the sidelines ever since as the U.S. spent more than $100 billion building a series of land- and sea-based interceptors.

An unresponsive U.S. plane with tail number N900KN crashed into the ocean north of Jamaica Friday afternoon.