Seoul: South Korean prosecutors on Thursday demanded a 15-year jail sentence for a nationalist activist who injured the US Ambassador to Seoul in a knife attack last March.

Kim Ki-Jong, 56, has been charged with attempted murder for his assault on Mark Lippert at a breakfast function in Seoul that left the ambassador needing 80 stitches for a deep gash on his cheek.

He has also been charged with promoting North Korea in breach of South Korea’s strict National Security Law that bans any act seen as aiding North Korea or promoting its ideology.

“The accused, wielding a deadly kitchen knife, repeatedly aimed at body regions that are directly related to sustaining life ... His intention to murder was explicit,” a prosecutor told the court.

Kim also aided the enemy through his action, the prosecutor added.

The prosecution alleges Kim promoted North Korea’s position that joint South Korea-US military drills are a rehearsal for an invasion of the North, and he assaulted the ambassador in order to stop the exercise.

But Kim denied he had had any intention to murder Lippert.

“I just wanted to kick up some ruckus before the breakfast function in order to attract his attention to [the demand the stopping of] the US-South Korea military exercises. I had no intention to kill him,” he said in a statement on Thursday ahead of a ruling due Friday next week.

Kim is a known maverick activist who had been handed a two-year suspended sentence in 2010 for hurling a rock at the then Japanese ambassador to Seoul.

Kim told investigators the ambassador was the “symbolic” target of his opposition to the annual US-South Korea military exercises, which he blames for blocking dialogue with North Korea.

Kim has visited the North seven times and once tried to erect a memorial in Seoul to the late North Korean leader Kim Jong-il after his death in 2011.

North Korea has rejected accusations that it may have been behind the attack on Lippert as a “vicious” smear campaign.