Kim hasn't made any public appearances since his apparent arrival in China on Friday, and it wasn't known who he was meeting or the make-up of his entourage. His rare foreign visits have always been shrouded in secrecy, and North Korean and Chinese government and official media kept mum.
Kim arrived in the city of Changchun by train early in the day and was shuttled by motorcade to the same state guesthouse where he had met with Chinese president Hu Jintao during a visit to the city in August.
South Korean media had initially speculated that Kim's son and heir apparent, Kim Jong Un, was either making a trip to China solo or accompanying his father. The elder Kim, 69, appears to have recovered from a reported stroke in 2008 and has resumed steady visits to factories and farms around North Korea. But travel outside his home country is rare.
This trip, however, would be Kim's third in a year to China, his country's main supporter and chief source of food and fuel assistance.
Kim's China visits are seen as a means to shore up support for his regime and faltering economy.