South Korea's intelligence agency assesses that North Korean leader Kim Jong-un has established his daughter, Ju-ae, as his likely successor when he allowed her to accompany him on his trip to China.

In a closed-door briefing to the National Assembly's Intelligence Committee on Thursday, the National Intelligence Service(NIS) said even though Kim's daughter refrained from outdoor activities while in Beijing, she solidified the narrative of her likely succession.

The NIS assessed that the North Korean leader is not currently experiencing any major health issues since he attended all the official schedules during his trip.

The agency noted, however, that the North was extra careful in terms of minimizing exposure of Kim and his daughter's biometric data.

When asked about rumors surrounding Kim's other children, the agency said it was unlikely that they have disabilities or are studying abroad.

The NIS also assessed that Kim believes he made a significant achievement during his trip to China by presenting himself as the leader of a "normal" state through solidarity with his Chinese and Russian counterparts.