The journey, which is believed to be Kim's first foreign trip since he came to power in 2011, adds a new piece to a complex diplomatic puzzle over the future of North Korea's nuclear program.
The announcement ends a mystery that started on Monday, when a mysterious train chugged into central Beijing, spurring reports of a high-profile visitor from North Korea.
The North's official Korean Central News Agency (KCNA) confirmed that the visitor was indeed Kim, along with his wife, Ri Sol Ju, arriving for an "unofficial" visit at the invitation of the Chinese president, Xi Jinping. The confirmation came sometime after the North Korean group is believed to have departed China.
Kim traveled with all his top aides, KCNA said, including Choe Ryong Hae, often called the No. 2 leader of North Korea and the head of the powerful Organization and Guidance Department, and Ri Su Yong, the former ambassador to Switzerland and foreign minister, who is now a top official in the Politburo