Kim Jong-Un misses key political event, feeding rumors about the North Korean leader's health

North Korean leader Kim Jong-Un missed another key political event Friday, extending a month-long absence and fuelling further speculation about his physical health and political future.

However South Korea said it believed Kim was still in full control of the nuclear-armed nation, and the North's state media lauded him as a model of "dignity and invincibility" whose authority was unquestioned.

Kim, believed to be 30 or 31, has not been seen since September 3 when he attended a music concert with his wife in Pyongyang.

Competing theories for his disappearance range widely from an extended rest period to a leadership coup, via a long list of possible illnesses and ailments including broken ankles, gout and diabetes.

The explanation with the most currency is a health issue that has left him temporarily incapacitated.

Kim was not listed by the state KCNA news agency among the officials who visited the mausoleum housing the remains of his father and grandfather -- an annual show of respect to mark Friday's anniversary of the ruling Korean Workers' Party foundation.

However, a floral tribute bearing Kim's name was presented to the two statues of Kim Jong-Il and Kim Il-Sung.

South Korea, which has largely distanced itself from the disappearance rumours, said it saw no indication that Kim was no longer in charge.

Unification Ministry spokesman Lim Byeong-Chul noted numerous reports in the North Korean state media of Kim exercising his authority.

"Judging from these, it seems that Kim Jong-Un is ruling normally," Lim said, adding that the government had no specific intelligence on Kim's health.

Kim's absence from the Kumsusan mausoleum visit was considered significant as he has attended each year since coming to power following the death of his father in 2011.

While he could still make an appearance later in the day, a complete no-show will likely send an already whirring rumour mill into overdrive.

Kim, a heavy smoker, has shown striking weight gain over the past year and recent TV footage had shown him walking with a pronounced limp.

-- No short-term impact --

Cheong Seong-Chang, an analyst at the Sejong Institute think-tank in Seoul, said Kim's absence was almost certainly down to a health problem that would have little impact on his leadership -- at least in the short term.

"But if he's forced to stay away for an extended period, it could cause murmurings within the political elite and weaken Kim's control," Cheong said.

In a front-page editorial on Friday, the Rodong Sinmun described Kim as the symbol of the ruling party's "dignity and invincibility", and said his authority should be protected by all means necessary.

"The steel-like unity of the party, with the leader at the centre, is the source of invincible power," the party mouthpiece said.

What little light North Korea has deemed necessary to shed on the rumours surrounding Kim's absence has only added to the confusion.

State media alluded at one point to his "discomfort", but one member of a top-level North delegation that visited South Korea last week insisted Kim had no health problem at all.

"He certainly doesn't want to be seen while he is sick and looking weak," said Bruce Bennett, a senior defence analyst with the RAND corporation.

"Looking weak is not good for a North Korean leader who is trying to maintain control," Bennett said.

The uncertainty means that every move or comment by North Korea is now seen through the unreliable prism of what it might say about Kim's situation.

Some saw the surprise visit by the high-ranking delegation as a message that all was normal in Pyongyang.

Others saw the presence of Kim's de-facto number two in the delegation as possible evidence that the leader may have been sidelined or pushed out altogether.

It is by no means unprecedented for a North Korean leader to drop out of the public eye for a while.

But it is more noticeable with Kim, who has maintained a particularly pervasive media presence since coming to power after the death of his father Kim Jong-Il in 2011.