US President Donald Trump has announced a a brand new fighter jet, the F-47, branding it the "most lethal jet ever built".

Making the announcement in the Oval Office, Trump told reporters: "The F-47 will be the most advanced, most capable, most lethal aircraft ever built. An experimental version of the plane is secretly been flying for almost five years, and we're confident that it massively overpowers the capabilities of any other nation.

"There's no other nation. We know every other plane I've seen every one of them, and it's not even close. This is the next level."