North Korean leader Kim Jong-un's China visit
Where is Kim Jong-un?KCNA via Reuters

South Korea will pay even closer attention to rogue neighbour North Korea's parliamentary session on 25 September, after reports that its supreme leader Kim Jong-un has not been seen in public for three weeks.

South Korean reports claim that the dictator has not been seen since attending a concert on 3 September with his wife Ri Sol Ju.

Eyebrows were raised over the thought to be 31-year-old's health after he was seen hobbling from a suspected leg injury during a ceremony marking the 20th anniversary of the death of his grandfather Kim Il Sung in July. He was also seen limping earlier in September.

Such is the suspiscion over his whereabouts, authorities south of the Korean border will use Thursday's meeting as an opportunity to monitor the leader, who has not missed a parliamentary session since being sworn into power in 2012.

"There's no way for the South Korean government to check Kim Jong Un's whereabouts as he hasn't appeared at public events," South Korean Unification Ministry spokesman Lim Byeong Cheol said.

Clampdowns on foreign press mean any news emanating from the secretive state is carefully selected by goverment broadcaster the Korean Central News Agency.

In August, the agency released the bizarre image of Jong-un at a visit to the Chonji Lubricant Factory.