The teenage daughter of North Korean leader Kim Jong Un has made her first known visit to a sacred family mausoleum, a step that some experts say bolsters her status as her father's potential heir.

The visit, which occurred on New Year's Day on Thursday, even sparked speculation that the girl, reportedly named Kim Ju Ae and aged about 13, could be named a high-level official at the upcoming ruling Workers' Party congress.

Ms Kim 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.

Images carried by North Korea's state media on Friday showed Ms Kim standing in the front row with her parents and deeply bowing at Pyongyang's Kumsusan Palace of the Sun in Pyongyang, where the embalmed bodies of her late grandfather and great-grandfather are on display.

Kim Jong Un, right, his wife Ri Sol Ju, left, and their daughter were also pictured watching a New Year celebration performance in Pyongyang.  (Korean Central News Agency/Korea News Service via AP)

The palace is "a place that symbolises legitimacy of the North Korean regime" and her visit there ahead of the Workers' Party congress is a politically orchestrated move, said Cheong Seong-Chang, deputy head of the private Sejong Institute in South Korea.

Mr Kim, 41, is the third generation of his family to rule North Korea since the country's foundation in 1948.

He often marks key state anniversaries by visiting the Kumsusan palace and paying respect to his father Kim Jong Il and grandfather Kim Il Sung.

Mr Cheong predicted that Mr Kim could give his daughter the first secretary post at the Workers' Party, the party's second-most-senior job, at the congress.

Other experts say she is too young to accept such a high-profile post and might be provided with lower-level jobs.

The congress, the first of its kind in five years, is meant to establish new priorities in state policies and reshuffle officials.

North Korea hasn't said when it will hold it, but the National Intelligence Service (NIS), South Korea's spy agency, said it will likely be held either in January or February.

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 Mr Kim's "stable family" by showing his wife and daughter alongside him at major events.

Kim Jong Un's daughter makes recent appearances

Ms Kim has been making increasingly prominent appearances in state media over the past three years.

Since her first appearance in November 2022, she has accompanied her father at a slew of events including military parades and missile launches.