The disturbing footage shows the launch of a rocket, believed to be an Intercontinental Ballistic Missile Photo: Mirror

A nuclear bomb strikes an American city, sending a huge fiery mushroom cloud soaring into the sky in a chilling World War 3 simulation aired in North Korea.

The worrying propaganda video was released as tensions continued to rise between Kim Jong-un's secretive country and the US.

The despot used the 'Day of the Sun' festival - marking the birthday of his late grandfather and tha nation's founder, Kim Il-Sung, to show off the strength of the North Korean army.

The disturbing footage shows a rocket, believed to be an Intercontinental Ballistic Missile (ICBM), wiping out an unspecified American city.

The sickening video - performance of the Korean State Merited Chorus - also shows the American Stars and Stripes in flames overlapped with an image of a cemetery.

The American Stars and Stripes is seen in flames Photo: Mirror

The choir unveiled a new song about the country's missiles which include the words "our proud Hwasong rocket blasts off" and "it flies as quickly as a flash of lightning to challenge imperialism".

North Korea attempted but failed to launch a missile on Sunday, the day after the military parade where what appeared to be new ballistic missiles were displayed.

"The North attempted to launch an unidentified missile from near the Sinpo region this morning but it is suspected to have failed," the South's Office of the Joint Chiefs of Staff said in a statement.

The US also confirmed the missile test.

Grainy footage sees a submarine launch the killer missile from the ocean before a fireball slams into Washington sending a mushroom cloud into the sky.

The bizarre four-minute video, titled 'Last Chance', was produced by top military officials in North Korea before being uploaded to Government website DPRK.

It starts with a backdrop of cheesy 90s techno music showing a montage of clips from the Korean War.

A message on the screen in Korean translates as: “If US imperialists move an inch toward us, we will immediately hit them with nukes.”

A digitally altered missile is then launched and soars through the sky before hitting the US capital, with the US flag bursting into flames.