 Kim Yong @-@ ju was believed to be Kim Il @-@ sung 's first choice as successor , and his authority increased until he became co @-@ chairman of the North – South Coordination Committee . From late 1972 until the 6th Congress , Kim Yong @-@ ju became an increasingly remote figure within the regime ; at the 6th Congress , he lost his seats in the Politburo and on the Central Committee . However , rumors were confirmed that Kim Il @-@ sung began grooming Kim Jong @-@ il in 1966 . From 1974 until the 6th Congress , Kim Jong @-@ il ( called the " Party centre " by North Korean media ) became the second @-@ most @-@ powerful man in North Korea . 
