In the report, CNN cited an unidentified "US official with direct knowledge" but did not provide any further details.

 

"There are no unusual signs in North Korea," a South Korean government official told Yonhap News Agency.

 

"It is not a fact."

 

Another official said there have been no signs detected with regard to Kim's health, emphasizing that the North's leader had continued to be seen in public until recently.

 

A South Korean presidential spokesman also said that no unusual signs have been detected about Kim's health.

 

The CNN report came after the Daily NK, a South Korean internet news outlet specializing in North Korea news, reported that Kim has been receiving medical treatment at a villa in the resort county of Hyangsan, outside of Pyongyang, following a cardiovascular procedure, said the Yonhap News Agency.

 

Speculation has increased about what happened to Kim since he apparently skipped an annual visit to the Kumsusan Palace of the Sun on the occasion of the 108th birthday of his late grandfather and state founder Kim Il-sung on April 15.

 

Kim was last seen on April 11 in state media reports presiding over a political bureau meeting of the ruling Workers' Party, calling for "strict national countermeasures to thoroughly check the infiltration of the virus."

 

He, however, did not attend a major session of the country's rubber-stamp parliament the following day, nor did state media report on his attendance in the country's latest weapons tests on April 14, a day before the late founder's birthday, an unusual absence given that he had mostly supervised such firings in recent months.

 

Kim has reportedly had health problems apparently linked to obesity and heavy smoking and his prolonged absence from public view has often spawned rumours about deterioration in his health, said the Yonhap News Agency report.

 

From early September 2014, he disappeared from the public eye for about 40 days and returned limping. Seoul's intelligence agency later said that he underwent surgery to have a cyst removed from his ankle.

 

Kim took over as leader of the communist state after his father Kim Jong-il died of a heart attack in late 2011.