Seoul, South Korea CNN  — 

Kim Jong Un’s sister Kim Yo Jong is effectively running one of the most important political bodies in North Korea, officials in Seoul believe, according to South Korea’s defense minister.

The development, if true, likely further cements her status as the secretive country’s second-most powerful figure.

Speaking to lawmakers in the National Assembly on Tuesday, Defense Minister Jeong Kyeong-doo said Kim Yo Jong is likely now in charge of the Organization and Guidance Department (OGD) of North Korea’s ruling Workers’ Party (WPK), the party body that deals with ideological indoctrination, party organization and political appointments.

Experts say the OGD is also responsible for monitoring the estimated 3 million members of the WPK to make sure they are sufficiently loyal to Kim Jong Un and respect the teachings of the North Korean regime.

Kim Yo Jong has for years been a trusted aide and confidante to her brother. She previously served as one of North Korea’s top propagandists and is now an alternate to the Politburo – the senior body of North Korea’s ruling party.

While North Korea and the ruling Workers’ Party often do not publicly proclaim leadership changes, experts and analysts had speculated previously that Kim may have been put in charge of the Organization and Guidance Department earlier this year, based on her increasing portfolio of responsibilities. Jeong, the South Korean defense minister, said Kim now appears to also have an important role in shaping policy toward South Korea and the United States.

Jeong’s comments appear in line with last week’s assessment by South Korea’s National Intelligence Service (NIS) that Kim Jong Un had decided to delegate more of his powers to senior officials surrounding him, including Kim Yo Jong, in order to ease his workload.

Talk of Kim Yo Jong’s increasing role in North Korean politics has previously fueled speculation about her brother’s health. Kim Jong Un historically has kept a grueling schedule filled with public appearances, but he disappeared a handful of times from the public eye earlier this year, sometimes for weeks on end. He also reportedly keeps a very unhealthy lifestyle.

North Korea is a notoriously opaque country without a free press, so absences that would be unusual in most of the world can occur in Pyongyang without official explanation. In fact, South Korea’s official assessments regarding Kim Yo Jong’s new job title come amid reports she was absent during multiple important government and party meetings this summer.

It’s not clear if her apparent disappearance is tied to her work earlier this summer, when she oversaw the destruction of an office used for dialogue between the two Koreas. The bombastic statement was believed to be in response to defectors sending anti-North Korean propaganda from inside of South Korea into North Korean territory.

Several experts believe Kim Yo Jong’s rising profile has been part of a carefully choreographed publicity campaign by North Korean state media to signal that she’s being groomed for something, but have been loath to connect her rising role to any speculation about Kim Jong Un’s demise.

There have been no signs that Kim’s grip on power has eased, Jeong said. Representative Kim Byung-kee, who attended the NIS briefing last week, said he was told that Kim Jong Un is still the ultimate authority in North Korea and exercises “absolute power.”

When asked about Kim Jong Un’s potential succession plans, Jeong told South Korean lawmakers Monday it would be “inappropriate for me to officially speak about that.