North Korean leader Kim Jong-un. Yonhap

South Korea is closely watching the whereabouts of North Korean leader Kim Jong-un, the unification ministry said Friday, as his absence from public view has stretched to three weeks once again.

A swirl of global rumors about Kim's heath and even the possibility of his death came to an end when he attended the completion ceremony of a fertilizer factory with a broad smile on May 1 after a 20-day absence from public view.

Speculation over his whereabouts has resurfaced as he has been out of public view for three weeks.

"The relevant authorities are keeping a close watch," Yoh Sang-key, the ministry's spokesperson, told a regular press briefing when asked whether or not the ministry is aware of Kim's whereabouts.

"There was a time in January when he was also absent from public view for 21 days so we are watching the situation over his absence from media reports," he said.

It is not rare for Kim to disappear from the public eye.

After his appearance at a concert in Pyongyang celebrating Lunar New Year's Day on Jan. 25, he was absent for three weeks until state media reported his visit to a mausoleum in Pyongyang to commemorate the birthday of his late father on Feb. 16.

His longest absence from public view was in September 2014, when he disappeared for 40 days and returned with a limp. Seoul's intelligence agency later said that he had a cyst removed from his ankle.

Rumors on his health have underlined the difficulty in figuring out affairs in the hermetic country, especially with regard to its leadership, and how easy it is for the outside world to slip into far-fetched speculation in the absence of clear information. (Yonhap)