SEOUL - North Korea put on a musical show to mark the birthday of founding father Kim Il Sung, which ended with a mock-up video of missiles engulfing the United States in flames, prompting cheers from the audience and smiles from current leader Kim Jong Un.North Korea's state television aired footage of a choral performance attended by Kim Jong Un, the elder Kim's grandson, on Sunday, a day after a huge military parade in Pyongyang, which also marked the 105th birth anniversary of Kim Il Sung.The singing was followed by footage of its test-firing of a missile in February which, in the video, was joined by other missiles shooting into sky, passing over the Pacific and exploding in giant balls of flames in the United States.The video ended with a picture of the American flag in flames, overlapping row after row of white crosses in a cemetery."When the performance was over, all the performers and participants in the military parade broke into enthusiastic cheers of "hurrah!" state run KCNA news agency said.State TV footage showed leader Kim smiling and waving in return."The Dear Supreme Leader waved back to them and congratulated the artistes on their successful performance," KCNA said.North Korea said in February that it had successfully tested a new type of medium- to long-range ballistic missile, the Pukguksong-2, propelled by a solid-fuel engine.During Saturday's military parade it displayed what appeared to be new intercontinental ballistic missiles. And a day later it conducted a failed missile test, which drew international condemnation.North Korea regularly threatens to destroy the United States and amid heightened tension on the Korean peninsula, it has escalated a war of words, warning of full-out nuclear war if Washington takes military action against it.US Vice President Mike Pence, on a trip to Asia, has repeatedly warned that the "era of strategic patience" with North Korea is over and on Wednesday said it would meet any attack with an "overwhelming response."