Kim’s health has been the focus of keen attention since Western intelligence officials said he suffered a stroke in August before publicly naming his successor. South Korean officials say he has recovered, yet the 67-year-old looked gaunt when he appeared at the country’s rubber-stamp parliament in April.

The U.S. informed Seoul that Kim had been staying at the villa in Wonsan since mid-May, the JoongAng Ilbo Sunday newspaper said, quoting an unidentified official privy to North Korean affairs. The report said U.S. military satellites, which closely monitor Kim’s personal vehicles, had detected his movement.

The official said it was "certain" that Kim was not in Pyongyang and that South Korean intelligence authorities believed Kim had stayed at Wonsan for a long time.