North Korea has revealed that leader Kim Jong Un's younger sister is a senior official in the ruling Workers' Party, strengthening analysts' views that she is an increasingly important part of the family dynasty that runs the country.

State media on Thursday referred to Kim Yo Jong as a departmental vice director within the party's Central Committee.

Analysts say the mention could signal her growing role in supporting her brother's authoritarian rule. The siblings' late father, former leader Kim Jong Il, was seen as relying on his own sister during his 17-year rule.

Outsiders closely study North Korea's opaque ruling power dynamics for clues about a secretive country that pursues nuclear weapons and threatens its neighbors with war.

The Korean Central News Agency first referred to Kim Yo Jong as a senior official in the Central Committee in March, but this is the first time state media have specified her role.

Yang Moo-jin, a North Korea expert at the University of North Korean Studies in Seoul, said a departmental vice director is roughly equivalent to a vice Cabinet minister. The announcement of Kim Yo Jong's role shows that the government is now confident enough to introduce her as an important part of its leadership, Yang said.

Cheong Seong-chang, an analyst at South Korea's private Sejong Institute, said Kim Yo Jong is likely to have greater influence than other departmental vice directors because she is a member of the Kim family. In establishing his sister in a senior role in the ruling party, Kim Jong Un is further strengthening his control of North Korea's power elite, Cheong said.