The country's top three military officials have been replaced with younger, more "moderate" figures who have more "flexibility in thinking" than their predecessors, according to an unnamed intelligence source quoted in the South Korean media.
Yonhap identified the three officials as defence chief Pak Yong-sik, chief of the Korean People's Army's (KPA) general staff Ri Myong-su, and director of the KPA's General Political Bureau Kim Jong-gak.
He described Pak and Ri as "leaders of the past, of Kim Jong Il's generation".
Ken Gause, director of the International Affairs Group at CNA, said: "If Kim Jong Un is set on making peace with the USA and South Korea and dealing away at least part of the nuclear programme, he will have to put the KPA's influence in a box and keep it there".More news: Petrobras CEO Resigns as Brazil Strike Engulfs Market Favorite
No had formerly overseen the military's financial issues as the chair of the Second Economy Commission, Kim said.
Political commissars under the bureau are stationed throughout the KPA and can influence the army's activity at all levels.
"If they think it enhances their legitimacy, then they certainly don't have a good understanding of the global community, and certainly what the U.S. is going to think about it", he said. "That was a problem during the sunshine period, a lot of misappropriation and malfeasance".
Kim's motivation remains unclear but analysts said the shake-up allows him and the ruling party to tighten control over the Korean People's Army (KPA) at a critical time of global engagement and domestic development.
A gathering of regional defense chiefs in the very same city where the two leaders of the United States and North Korea are due to meet in a mere 10 days' time.More news: UK food, fuel, medicine short under 'no deal' Brexit
Yonhap reported that Kim Yong Chol had transited Beijing on Monday on his way back to Pyongyang from the United States. "We can go fast, we can go slowly".
Trump said one thing that could come out of the summit is an agreement formally ending the 1950-53 Korean War, which was concluded only with a truce, not a peace treaty.
South Korea's Yonhap news agency first reported the move. It's also not clear how long the talks will last.
In 1971, Idi Amin famously seized power in Uganda while President Milton Obote was in Singapore for a meeting of Commonwealth leaders.
"I am sure that he will achieve the final victory and realize the reunification of Korea without fail", Assad reportedly said.More news: Guatemala volcano eruption: How often does Volcan de Fuego erupt?