North Korean leader Kim Jong Un has aggravated a leg injury he suffered in late August or early September that needs three months to heal, but remains fully in charge of the country, a source with access to the North's leadership said.

North Korea's state media, which usually chronicles the 31-year-old's whereabouts in great detail, has not made any mention of Kim's activities since Sept. 3, fuelling speculation that he may be in ill health or his grip on power may be slipping.

"Kim Jong Un is in total control," said the source, who has close ties to Pyongyang and Beijing and direct access to the top levels of both governments. "There is no split in the top leadership."

"He injured his ankle and knee around late August or early September ... because he is overweight. He limped around in the beginning but the injury worsened," the source said.

"He has difficulty walking and needs about 100 days to recuperate."

Speculation that Kim's unusually long absence from public view may be due to ill health increased when a North Korean TV report late last month said he was suffering "discomfort".

Some Pyongyang watchers also suggest that Kim may have been sidelined in a power struggle, a scenario they say was reinforced by the unexpected visit on Saturday of a high-level delegation to Incheon, South Korea.

"The DPRK is absolutely stable, a lot more stable than in the past," the source said, using the short form for the North's official name, the Democratic People's Republic of Korea. "Rumours about a coup and that Kim Jong Un is dead are rubbish."

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