North Korean leader Kim Jong-un’s choice of his young daughter, Kim Ju-ae, as his heir is expected to spark internal tensions within the ruling family, according to a former South Korean intelligence official.

Kim Ju-ae, believed to be 13, has been increasingly visible at official events, signaling that she may be groomed to succeed her father. South Korea’s National Intelligence Service (NIS) informed parliament this week that the North Korean leader has reportedly selected her as his successor.

Rah Jong-yil, former South Korean ambassador to the UK and deputy director of Seoul’s intelligence service, warned that Ju-ae could face opposition from her aunt, Kim Yo-jong, who is widely regarded as ambitious and politically ruthless.

“It depends on the timing, but I believe if Kim Yo-jong believed that she had a chance of becoming the top leader then she would take it,” Rah said. “For her, there are no reasons to refrain from putting into effect her own political project.” He added that a power struggle “is probable.”

Kim Yo-jong, 38, holds considerable political and military influence within the Workers’ Party of Korea, making her the country’s second most powerful figure. Analysts say her strong backing gives her an advantage should Kim Jong-un die or become incapacitated.

The North Korean leadership has a history of violent family disputes over succession. In December 2013, Kim Jong-un executed his uncle, Jang Song-thaek, on charges of “anti-party, counter-revolutionary, factional acts.” Similarly, Kim Jong-nam, the older half-brother of the current leader, was assassinated in 2017 in Kuala Lumpur.

Kim Ju-ae has been seen alongside her father at high-profile events, including military parades and missile tests, as well as diplomatic occasions like the 80th anniversary of North Korea’s air force. South Korea’s NIS highlighted her “increasingly prominent public presence at official events” as evidence that she has been designated as a successor.

Officials suggest her attendance at North Korea’s upcoming party congress, the nation’s largest political event, could further indicate her status in the succession plan.

There has been ongoing speculation about why Kim Jong-un, 42, is naming a successor at a relatively young age. Reports suggest he suffers from health issues, including diabetes, high blood pressure, and obesity, similar to the conditions that afflicted his father, Kim Jong-il, who died at 70.

A report published by 38 North, the website of the US-based Stimson Centre, cautioned that Kim’s sudden death could lead to turbulence within North Korea’s leadership. It noted a “high likelihood of a power struggle emerging between Kim Jong-un and his potential successor candidates,” highlighting Kim Yo-jong as the politically established figure most likely to assume control in the near term.

Other potential heirs, including Kim Ju-ae and her presumed younger siblings, “are still too young and unestablished to realistically be considered for succession in the coming five to 15 years,” the report added. It concluded, “Kim Yo-jong, for example, will be able to immediately outmanoeuvre the others due to the political and military support she has garnered within the [Workers’ Party of Korea].”