Trump wrote on Twitter, sharing images of Kim released by the North Korean state news agency. He was reportedly last seen on state media on April 11. On that day, the North marks the birthday of his grandfather Kim Il-sung, the country's founder.
KCNA said Kim attended Friday's ceremony marking the completion of a fertilizer factory near Pyongyang along with senior officials.
The Korean Central news agency said that onlookers "broke into thunderous cheers of 'hurrah!'" when Kim appeared. "And we are also maintaining a necessary readiness posture", the JCS noted.
The two sides are now in talks via a military communication line, Yonhap News reported.
Where it stands: Photos from the ceremony have not been released, AP reports, and Kim's appearance has not been independently verified. The government has repeatedly sought to downplay rumors regarding Kim's health.
The fertilizer plant has been the subject of attention for years because of its potential dual-use in the process of uranium extraction from phosphoric acid, allowing North Korea to hide its nuclear activities from the outside world. The reason North Korea opened fire remains unknown.
South Korea responded by firing two shots towards North Korea.
Despite reports of Kim's good health, the North Korean leader is plagued by the same troubles before his disappearance.
Image Kim Jong Un was surrounded by officials during his visit to a fertiliser plant
Photos and video showed the 36-year-old leader strolling and smiling as thousands of North Koreans cheered.
"He's returned, so we can disprove that he's dead, but that's pretty much it, we can't got much further than that".
President Donald Trump was pleased to hear that North Korean leader Kim Jong-Un had returned to the public eye after weeks of health rumors.
The youngest child of their father, Kim Jong-il, Ms Kim was reported to be the figure lined up to replace her brother if he died.
Fifield said that while some might accuse China of taking advantage of a vacuum in North Korea, it had many reasons to keep the region stable.
Kim's purported reappearance comes as the world battles the coronavirus pandemic, with the North insisting that it has not seen a single case - although experts say it is unlikely. But the aunt, Kim Kyong-hui, re-emerged in Pyongyang in January.
Initial testing finds coronavirus antibodies in 21.2% of New York City’s populace
Centers for Disease Control and Prevention has estimated that 25% of people may be asymptomatic for the disease. The tests showed 13.9% overall had them, which would translate to possibly 2.7 million people in the state.