North Korean leader Kim Jong-un has reportedly appeared in public for the first time in 20 days amid mounting rumors and reports that he was gravely ill.

The North's official Korean Central News Agency(KCNA) and other state media reported on Saturday that Kim attended the completion of a fertilizer plant in Suncheon, north of Pyongyang, on Friday. 

The KCNA said that Kim cut a ribbon at the ceremony marking the completion of the factory, unveiling photos of Kim cutting the ribbon and talking to officials accompanying him.  

The report said that Kim expressed satisfaction about the production system of the factory, saying the plant made significant contribution for the progress of the country's chemical industry and food production.

It added that Kim was accompanied by several senior officials, including his younger sister Kim Yo-jong.

It marks the first report of Kim's public activity since April 11 when he presided over a politburo meeting of the ruling Workers' Party. There has been speculation about Kim's health after he missed the birth anniversary celebrations of his grandfather, state founder Kim Il-sung on April 15.