All top three North Korean military generals have been replaced ahead of the 12 June summit in Singapore, the first meeting between sitting officials of the US and North Korea.
Trump has revived the Singapore summit on Friday after cancelling it a week earlier.
South Korea's Yonhap news agency, citing an unnamed intelligence official, reported that defense chief Pak Yong Sik had been replaced by No Kwang Chol, while Ri Myong Su, chief of the Korean People's Army (KPA) general staff, had been replaced by his deputy, Ri Yong Gil.
Army general Kim Su Gil's replacement of Kim Jong Gak as director of the KPA's general political bureau was previously referenced in North Korean state media, and confirmed Monday by South Korea's Unification Ministry, which deals with North Korean affairs.
"All these (promoted) guys are top Kim Jong Un guys," said Michael Madden, author of the highly respected North Korea Leadership Watch blog. "All three of them have held very sensitive and high level positions under Kim Jong Un, they're very loyal (to him), and all have experience interacting with foreign delegations."
US President Donald Trump insists that American sanctions and military pressure are the reason North Korea is now willing to negotiate directly on giving up its nuclear weapons.
But it doesn’t seem that way from North Korea's point of view.