North Korean leader Kim Jong-un missed an event at the Kumsusan Palace of the Sun on Tuesday to celebrate his late father's birthday.

The official [North] Korean Central News Agency listed the names of party, government and military leaders who paid their respects at the elder Kim's embalmed corpse, but his son's was not among them.

Kim has previously visited the palace at the stroke of midnight on his father's birthday every year.

"This is very unusual," a Unification Ministry official here said.

Also absent was Workers Party secretary Choe Ryong-hae, who only recently reappeared after months off the radar.

Choe was also the only top official not to attend a banquet hosted by Kim Jong-un on Sunday for the scientists behind the recent rocket launch and a major mass rally on Monday.

But Choe appears to be in poor health, so it is uncertain whether he has yet again fallen from favor or was absent for health reasons.

