North Korean leader Kim Jong Un’s daughter, is being groomed to succeed him, according to South Korea’s National Intelligence Service.

The assessment provides one of the clearest indications yet of how North Korea’s ruling family may be preparing for a future leadership transition, while also shedding more light on the structure of the Kim dynasty.

The NIS said on Thursday that it believes Kim Ju Ae has a younger sibling, although the agency does not yet know whether the child is a boy or a girl.

“The National Intelligence Service currently assesses that Kim Ju Ae is being groomed as the successor,” the agency said, adding that it understands she has a younger sibling whose gender remains unknown.

South Korean intelligence has previously assessed that Kim Jong Un has three children, but there has been uncertainty surrounding their birth order, identities and roles within the ruling family.

The latest assessment suggests that Kim Ju Ae is currently the most prominent of the leader’s children and the one being positioned for a potential future leadership role.

Kim Ju Ae was first publicly introduced in 2022 when she appeared alongside her father during an event marking the launch of a North Korean intercontinental ballistic missile.

Since then, her public appearances have increased significantly.

She has accompanied Kim Jong Un at several major state and military events, including high-profile occasions involving North Korea’s strategic weapons programme. She also attracted international attention during a prominent visit to Beijing.

However, the NIS said it was still investigating whether Kim Ju Ae has an older brother.

The agency said that even if an older brother exists, it does not currently believe he is in a position to succeed Kim Jong Un.

North Korea has been ruled by the Kim family since the country was established, with power passing from Kim Il Sung to his son Kim Jong Il and later to Kim Jong Un.

The ruling dynasty has built its legitimacy around what it describes as the “Paektu bloodline,” named after Mount Paektu, a mountain deeply embedded in North Korean state mythology and the Kim family’s official narrative.

Leadership succession in the highly secretive country is therefore closely watched, particularly because there is no transparent political process through which the public can determine who will eventually take over.

Kim Ju Ae’s growing visibility has consequently generated widespread speculation about whether Kim Jong Un is gradually introducing her to the North Korean public and political elite as his eventual successor.

Her appearances alongside senior officials and at major military events have been interpreted by outside analysts as part of a deliberate effort to familiarise the country with the next generation of the Kim dynasty.

Still, South Korea’s intelligence assessment does not provide a definitive timeline for any succession, and Kim Jong Un remains firmly in control of North Korea.

The identity and role of his other children also remain largely hidden from public view.