North Korea defectors come under criticism over speculating Kim Jong-un's fate

A former senior North Korean diplomat apologised on Monday after saying leader Kim Jong-un was likely so ill he could not stand, days before he emerged in state media chain-smoking and walking briskly at an event attended by hundreds of officials, reported news agency Reuters.

Kim disappeared from state media for three weeks, sparking wild rumours about his health and whereabouts, and worry about prospects for the nuclear-armed state in the event of an unexpected succession.

But on Saturday, North Korean media published photographs and video of Kim at a ribbon-cutting ceremony for the inauguration of a fertiliser plant.

His re-emergence came as a blow to the credibility of some high-profile defectors from the North who had speculated that Kim was suffering from a grave illness or could even be dead, the report added.

One of the defectors, Thae Yong-ho, was North Korea's deputy ambassador to Britain, where he managed secret funds for Kim. Thae fled to South Korea in 2016 and was one of a pair of defectors elected to parliament last month.

"I am aware that one of the reasons why many of you voted for me as a lawmaker is with the expectations of an accurate analysis and projections on North Korean issues," Thae said in a statement. "I feel the blame and heavy responsibility."

"Whatever the reasons, I apologise to everyone."

The other prominent defector elected to parliament, Ji Seong-ho, had said in a media interview he was 99% certain that Kim had died after cardiovascular surgery and an official announcement would come as soon as Saturday.

Daily NK, a Seoul-based news outlet with sources inside North Korea, reported in April that Kim was recovering from a cardiovascular procedure.

Ji, who was invited to attend US President Donald Trump's State of the Union address in 2018, issued a statement to apologise.

"I have pondered on myself for the past few days, and felt the weight of the position that I'm in," Ji said.

"As a public figure, I will behave carefully going forward."

South Korea's ruling Democratic Party criticised the pair for carelessness and said their mistake could do more serious harm than just misinforming the public.