The U.S. ambassador to South Korea left a Seoul hospital Tuesday, five days after he was slashed by a knife-wielding Korean nationalist with a history of violent protest, causing wounds that required 80 stitches to the envoy's face.

Police are seeking to bring charges including attempted murder against Kim Ki-jong, 55, for the attack at a forum discussing Korean reunification. The ambassador, Mark Lippert, suffered a deep facial gash and a puncture wound on his wrist.

Lippert, 42, had become known for an approachable, informal style since taking up his posting in Seoul in November and the attack raised questions about his security arrangements.