South Korea’s spy agency has told lawmakers that it believes the teenage daughter of the North Korean leader, Kim Jong-un, is close to being designated as the country’s future leader as Kim moves to extend the family dynasty to a fourth generation.

The assessment by the National Intelligence Service comes as North Korea is preparing to hold its biggest political conference later this month, where Kim is expected to outline his main policy goals for the next five years and take steps to tighten his authoritarian grip.

In a closed-door briefing, NIS officials said they were closely monitoring whether Kim’s daughter, believed to be named Kim Ju-ae and about 13 years old, would appear with him before thousands of delegates at the upcoming Workers’ party congress, said Lee Seong Kweun, a lawmaker who attended the meeting.

Ju-ae first appeared in public at a long-range missile test in November 2022 has since accompanied her father to an increasing number of events including weapons tests, military parades and factory openings. She travelled with him to Beijing last September for Kim’s first summit with Xi Jinping in six years, on the sidelines of a second world war memorial event.

Speculation about her political future intensified last month when she joined her parents on a New Year’s Day visit to Pyongyang’s Kumsusan Palace of the Sun, a sacred family mausoleum displaying the embalmed bodies of her late grandfather and great-grandfather, the country’s first- and second-generation leaders. Some experts saw the visit as the clearest sign yet that she was positioned to be the heir to her 42-year-old father.

South Korean officials initially expressed doubt that she could be chosen as a North Korean leader, citing the country’s deeply conservative culture and tradition of male-dominated leadership. But her increasingly prominent appearances in state media have prompted a reassessment.

In its previous assessment of Ju-ae’s status, in September the NIS told lawmakers that Kim’s decision to bring her along on his trip to China was probably part of an effort to build a “narrative” possibly paving the way for her succession.

Lee said: “In the past, [the NIS] described Kim Ju-ae as being in the midst of ‘successor training’. What was notable today is that they used the term ‘successor-designate stage’, a shift that’s quite significant.”

According to Lee, the agency cited her growing presence at high-profile military events, her inclusion in the family visit to Kumsusan, and signs that Kim was beginning to seek her input on certain policy matters.

Not much is known about Kim’s daughter. Despite her increased visibility in propaganda, North Korean state media have never published her name, referring to her as his “respected” or “most beloved” child.

The belief that she is named Kim Ju-ae is based on an account by the former NBA star Dennis Rodman in which he recalled holding Kim’s baby daughter during a trip to Pyongyang in 2013. South Korean intelligence officials believe she was born sometime that year.

In 2023, South Korea’s spy agency told lawmakers that Kim and his wife also likely have an older son and a younger third child whose gender is unknown.

Since its foundation in 1948, North Korea has been ruled by male members of the Kim family, beginning with the country’s founder, Kim Il-sung, and followed by his son, Kim Jong-il.

Kim Jong-un was just 26 when he was officially named heir during a 2010 party conference, two years after Kim Jong-il had a debilitating stroke. After his father’s death in December 2011, Kim Jong-un was abruptly thrust into the throne with relatively little preparation.

Some analysts suggest Kim’s decision to debut his daughter early may reflect his own experience of being rushed into power.