SEOUL, South Korea — Kim Jong-un, the North Korean leader, is “not feeling well,” a state-run television station reported this week, in a rare revelation about his health.

In a documentary broadcast on Thursday, the North’s Central TV showed Mr. Kim, who has not been seen in public in recent weeks, walking with a limp while visiting a factory in Nampo, a provincial town southwest of Pyongyang, the North Korean capital, last month. A narrator intoned about the tireless work of Mr. Kim, “our marshal, who lights the path of leadership for the people like a flame, although he was not feeling well.”

Central TV, a key channel of government propaganda, mentioned Mr. Kim’s physical trouble in the context of what it called his selfless dedication to his people. Still, it was so rare for the news media in North Korea to discuss the condition of the supreme leader that Thursday’s report was widely picked up by the South Korean media on Friday.

North Korea’s tightly controlled media never mentioned the health conditions of Mr. Kim’s grandfather and father, who ruled before him and suffered various ailments, like diabetes. Video footage and photos never revealed a large cyst that Mr. Kim’s paternal grandfather, Kim Il-sung, developed on the back of his head in his later years.