Kim's daughter Ju Ae has long been seen as the next in line to rule the secretive, nuclear-armed state, and took part in a string of recent high-profile outings, including this week's military parade marking the closing stages of North Korea's key party congress.

Pyongyang's official Korean Central News Agency (KCNA) released a photo of Ju Ae shooting a rifle at an outdoor shooting range, peering through a rifle scope with her finger on the trigger, smoke rising from the barrel.

She was wearing what appeared to be a leather jacket, a garment often worn by both her and her father at major political events, symbolising authority and legitimacy.

KCNA reported on Saturday that Kim presented new sniper rifles to senior party and military officials, describing the move as a gesture of appreciation and "absolute trust," without mentioning Ju Ae.

He then visited a shooting range with the officials, where he fired the rifle and took a group photo, it added.

South Korea's spy agency said this month that Pyongyang appears to have started the process of designating Ju Ae as leader Kim's successor.

By underscoring Ju Ae's ability to handle and fire a weapon, the photos "suggest she is indeed receiving training as a successor", Yang Moo-jin, former president of the University of North Korean Studies in Seoul, told AFP.

KCNA also said Saturday that Kim Jong Un's powerful sister Kim Yo Jong will head the party's general affairs department -- a role analysts describe as akin to a party secretary-general.

The Kim family has ruled North Korea with an iron grip for decades, and a cult of personality surrounding their "Paektu bloodline" dominates daily life in the isolated country.