A North Korean propaganda unit said the U.S. ambassador to South Korea could face a 'bigger mishap ' than the knife attack to his face last month if he does not stop insulting North Korea with 'laughable ' accusations . U.S. envoy Mark Lippert said in a speech on Wednesday that if North Korea improves its human rights record and takes steps to end its nuclear program , it will be rewarded with prosperity and better ties with the outside world , including the United States . The North 's Committee for the Peaceful Reunification of Korea said Lippert 's remarks were proof that Washington was intent on hostility . Scroll Down for Video . US Ambassador to South Korea Mark Lippert ( center ) looks on as US Defence Secretary Ashton Carter ( R ) shakes hands with 7th Air Force Commander Lt. Gen. Terrence J. O'Shaughnessy ( L ) and US Army Gen. Curtis Scaparrotti ( 2nd L ) , commander of the United Nations Command , South Korea-U.S . Combined Forces Command and U.S . Forces Korea last week . 'Lippert needs to drop the bad habit of rashly engaging in scheming chatter distorting the truth and instigating war by taking issue with us , ' the committee said in a commentary published on Thursday on the Uriminzokkiri propaganda web site . 'Otherwise , next time , he could face a bigger mishap than getting cut in the cheek by a South Korean citizen , ' it said . The North frequently rails at the United States , the South 's biggest ally , accusing it of preparing for imminent invasion . The U.S. Embassy in Seoul did not have any immediate comment . US ambassador Mark Lippert , 42 , on his discharge from hospital after being attacked by a knife-wielding activist in March . Lippert was slashed in the face with a fruit knife by a South Korean man with a history of erratic behaviour at a breakfast forum in central Seoul that left a gash that required 80 stitches . He also suffered injuries to his arm . 'It is unbearable insult and mockery against us and a laughable and brazen charge that can not be overlooked , ' the North 's agency said . South Korean police charged Lippert 's attacker with attempted murder . He was not charged with any North Korea-related crime after being questioned over his multiple visits . North and South Korea are technically still at war after their 1950-53 conflict ended in a truce , not a peace treaty . Mark Lippert suffered a deep facial gash and stab wound to his wrist after being attacked by a knife wielding pro-North Korean during a breakfast forum in Seoul in March . The 42-year-old needed 80 stitches to the deep knife wound to his face after the attack . North Korea previously called the attack 'deserved punishment ' but denied any role in it . In March , Lipper said that he was pretty darn good ' as he was released from hospital . Mark Lippert suffered a deep facial gash and stab wound to his wrist after being attacked by a knife-wielding pro-North Korean activist during a breakfast forum in Seoul last week . Speaking as he left Seoul 's Severance Hospital the ambassador said he felt 'pretty darned good , all things considered , ' after the 'scary incident . ' The 42-year-old , whose face was bandaged and had his arm in a brace , needed 80 stitches after being set upon . Mr Lippert refused to comment about the attack as he left hospital due to the on-going police investigation . The alleged attacker , known as an anti-U.S. activist who was previously convicted of hurling a piece of concrete at the Japanese ambassador in Seoul in 2010 , was arrested at the scene . Police are seeking to bring charges including attempted murder against Kim Ki-jong , 55 , for the attack at a forum discussing Korean reunification . Police said the motive for Kim 's action was not known , but he shouted after the attack that he opposes the ongoing annual U.S.-South Korea military drills that North Korea condemns as a preparation for a northward invasion .
Mark Lippert was attacked in early March by a knife-wielding pro-North Korean activist . The attack happened at the University of California, Berkeley, where he is an assistant professor and director of its Center for International Studies.