South Korea's leader is publicly asking Pyongyang to help close the book on a war that never officially ended. President Lee Jae Myung used a Liberation Day speech on Saturday to invite North Korea to talks on formally declaring the Korean War over and replacing the 1953 ceasefire with a lasting "peace regime," reports the Guardian. Lee suggested setting up a "multi-layered security system" to prevent clashes along the DMZ and also proposed the talks as a place to hash out concrete steps to curb the North's nuclear program, reports the BBC. The offer comes as North Korea continues regular missile tests and insists its nuclear arsenal is non-negotiable. It has previously dismissed Lee's outreach and has not commented on the new proposal.