After Kim Jong Un was seen limping in July at an event marking the 20th anniversary of his grandfather Kim Il Sung's death, rumors have been rife that he is suffering from various ailments. Reuters

As the world ponders the whereabouts of North Korean leader Kim Jong Un, who disappeared from the public eye more than a month ago, reports suggest his sister, Kim Yo Jong, might be in charge of the hermetic country. The 31-year-old leader was last seen in public with his wife, Ri Sol Ju, at a concert in Pyongyang on Sept. 3.

After Kim was reportedly seen limping at an event in July marking the 20th death anniversary of his grandfather and North Korea's founder Kim Il Sung, reports have suggested that he may be suffering from various health issues, such as gout and diabetes. Kim’s disappearance has also fueled speculation that his younger sister could be temporarily in charge of North Korea while he recovers from an illness, CNN reported, citing the North Korea Intellectuals Solidarity, or NKIS, a group of North Korean dissidents living in South Korea.

“I can see how it's possible that she's in some sort of temporary position,” CNN quoted Victor Cha, an analyst with the Center for Strategic and International Studies, as saying. “It's very difficult for the North Korean system to run without one of the Kim family at least titularly in charge. So, if Kim Jong Un is indisposed, she's really the only available body that's left, in terms of a direct Kim family line.”

Michael Madden, a North Korea specialist who runs a blog called “North Korea Leadership Watch,” reportedly said that the country’s media has been identifying Kim Yo Jong as the deputy director of the Workers' Party, which is considered a very powerful position in the country's political hierarchy. Kim Yo Jong, who attended private school in Switzerland with her brother, has experience in handling critical positions and administrative duties in the government, according to CNN.

However, some North Korea-watchers believe that Kim Yo Jong is too young to be leading the country as the stress within the North Korean administration could be overwhelming.

“If in fact she is running the country -- as someone in their early to mid twenties, to me that is quite alarming,” Cha told CNN. “It means there is something seriously wrong with Kim Jong Un and there is some sort of void that they're desperately trying to fill.”

This is not the first time that speculation about Kim Yo Jong taking over state duties has emerged following reports about Kim Jong Un’s illness. The Diplomat, a Tokyo-based magazine, reported last week that Kim’s younger sister might be leading the country instead of her brother.

“Some say Hwang Byong-so, director of the General Political Bureau of the Korean People’s Army, may have assumed new No. 2 status, but given what has been confirmed this time, we can say Hwang is just a shadow, and Kim Yo-jong is the second-in-command of North Korea,” Kim Heung Gwang, the head of NKIS, told the Diplomat.