The Daily NK, an online news periodical based in Seoul, which is run mostly by North Korean defectors, reported that Kim, 36, was recovering from his April 12 surgery at a resort county villa on the east coast. The report said Kim has been in bad health because of heavy smoking, obesity and overwork.
Sources told Fox News that the White House is aware of the reports of Kim's health, but there is no confirmation.
Specifics on Kim's condition were unclear; North Korea has been notorious for withholding and distorting news inside its borders.
Kim missed a key anniversary event last week. The national holiday is the anniversary of the birthday of the remote kingdom's founder Kim Il Sung, Kim’s grandfather.
It's a day that normally includes an immense military parade and synchronized public performances, sometimes involving tens of thousands.
Kim’s apparent absence raised questions about whether coronavirus played a part.
Fox News' John Roberts and Edmund DeMarche contributed to this report