North Korea leader Kim Jong Un's daughter makes public visit to state mausoleum

North Korean leader Kim Jong Un's daughter, Ju Ae, who is likely being prepared as his successor, accompanied her parents on her first public visit to the Kumsusan mausoleum to pay respects to former leaders, state media photos published on Friday showed.

Ju Ae has been making increasingly prominent appearances in state media over the past three years, fuelling speculation by analysts and South Korea's intelligence agency that she may be in line to be the country's fourth-generation leader.

Cheong Seong-chang, vice president at the Sejong Institute think tank, viewed Ju Ae's first presence at the Kumsusan palace as her father's calculated move ahead of the upcoming ruling party Congress at which her succession might be formalised.

Kim was also accompanied by his wife, Ri Sol Ju, and senior officials on the visit on January 1, with Ju Ae between her parents in the main hall of the Kumsusan Palace of the Sun, state news agency KCNA photographs showed.

Hong Min, an expert on North Korea at the state-run Korea Institute for National Unification, said North Korea had been portraying an image of Kim's "stable family" by showing the wife and the daughter along with Kim on major events.

Kim Ju Ae, who is believed to have been born in the early 2010s, attended this year's New Year celebrations, according to state media on Thursday. In September, she travelled to Beijing with her father on her first public overseas outing.

Kim visits Kumsusan to honour his grandfather and state founder, Kim Il Sung, and father Kim Jong Il on key dates and anniversaries in a gesture affirming the dynastic heritage of the nuclear-armed country.

North Korea has never confirmed Ju Ae's age.

South Korea's Unification Ministry spokesperson declined to comment on Ju Ae's appearance. An official told reporters the government's view is it is too early to say she is a successor, given her age and she does not hold an official position.

Hong said potential roles of Kim's other children have left room for caution in drawing conclusions about Ju Ae's succession.

"It's practically impossible to publicly designate Kim Ju Ae, who is believed to have just turned 13, as the successor when she's not even old enough to join the (Workers') Party," Hong said.