SEOUL (Reuters) - North Korea released footage on Thursday (Feb 11) showing leader Kim Jong Un travelling on his private jet to supervise preparations for Sunday's long-range rocket launch and provided a rare view of the country's newly upgraded space centre on the east coast.

The footage on North Korean state TV also showed the lift-off of the Kwangmyongsong rocket from a newly expanded launch tower and what appeared to be the first-stage booster separating from the rocket as it flew into space, seen from an onboard camera.

"The dignity of Paektu shot to space carrying our satellite Kwangmyongsong-4," a narrator said in an excited voice as fast-tempo music played in the background.

Paektu refers to the mountain on the China border, seen as the birthplace of the North's revolution led by three generations of the Kim family.

Mr Kim, who is believed to be 33, was shown having discussions with military aides onboard as he flew to the Tongchang-ri rocket station on a Russian-built Ilyushin jet that had been previously depicted in state media as his private jet.

The top military officers from the United States, South Korea and Japan said on Wednesday that North Korea's fourth nuclear test on Jan 6 and Sunday's launch were direct violations of United Nations resolutions and "serious provocations against the international community".

The head of the US Army's Missile Defense Command said on Wednesday that a satellite put into orbit by North Korea at the weekend did not appear to be transmitting, but it was worrying that the rocket that took it there delivered twice the payload of Pyongyang's previous launch in 2012.

The Tongchang-ri space station was seen to have undergone upgrades to erect a taller launch tower and add covered rocket processing buildings that made possible the assembly of the three-stage rocket largely out of sight of spy satellites.