North Korean state media has released a new video depicting the destruction of US aircraft and warships and warning that any attack on it will see US forces "head to the grave".

The 99-second clip was released on Sunday by the DPRK Today news site, just hours after two US Air Force B-1B Lancer bombers flew off the coast of the country in a show of force.

Accompanied by US fighters based in Okinawa, the bombers flew further north of the demilitarised zone that divides the Korean Peninsula than any other US military aircraft in the 21st century, according to the Pentagon.