South Korea has said Kim Jong Un is "alive and well", casting doubts again on speculation that the North Korean leader is seriously ill after undergoing heart surgery.

"Our government position is firm," Moon Chung-in, the top foreign policy adviser to South Korean President Moon Jae-in, told CNN.

"Kim Jong Un is alive and well. He has been staying in the Wonsan area since 13 April. No suspicious movements have so far been detected."

'China would like to see N Korea more docile'

Kim, 36, was last seen in public on 11 April at a meeting of the ruling Workers' Party politburo.

But when the country celebrated the birthday of his late grandfather and state founder Kim Il Sung four days later, he was absent.


Since then there have been conflicting accounts about his whereabouts and health, fanned by his heavy smoking, apparent weight gain since taking power and family history of cardiovascular problems.

CNN last week reported that Kim was in "grave danger" following the surgical procedure, citing an anonymous US official.

Daily NK, a website run mostly by North Korean defectors, also said last week that Kim was recovering at a villa in Hyangsan County in North P'yongan province after having surgery on 12 April.

Image: South Koreans in Seoul watch a news report on the speculation about the North Korean leader's health

News agency Newsis cited South Korean intelligence sources on Friday as reporting that a special train for Kim's use had been seen in Wonsan, while the dictator's private plane remained in Pyongyang.

The agency reported that Kim may be sheltering from COVID-19, the respiratory disease caused by the coronavirus.

A report by 38 North, a Washington-based project that monitors North Korea, said: "The train's presence does not prove the whereabouts of the North Korean leader or indicate anything about his health but it does lend weight to reports that Kim is staying at an elite area on the country's eastern coast."

Image: Satellite images show what may be the train belonging to Kim Jong Un in Wonsan. Pic: Airbus Defence & Space and 38 North/Pleiades © CNES 2020, Distribution Airbus DS

Reporting from inside North Korea is notoriously difficult because of tight controls on information within the secretive state.

Kim, a third-generation hereditary leader who came to power after his father's death in 2011, has no clear successor in his nuclear-armed country. This could present a major international risk.

He has disappeared from coverage in North Korean state media before.

Kim vanished for more than a month in 2014 and North Korean state TV later showed him walking with a limp.