U.S. says alliance with S. Korea "strong" despite attack on envoy

The alliance between the United States and South Korea is "strong" and the two countries "will not be deterred by senseless acts of violence," the U.S. State Department said Thursday.

U.S. ambassador to South Korea Mark Lippert was injured on Thursday in a knife-wielding attack by a South Korean male assailant who shouted opposition to the ongoing U.S.-South Korea joint annual war games.

Lippert underwent surgery later in the day to treat wounds to his face and hand and is currently recovering in the hospital in Seoul, State Department spokeswoman Marie Harf said in a statement.

Lippert tweeted Thursday afternoon from Seoul, saying that he is "doing well&in great spirits."

Lippert looks forward to getting back to work with his South Korean counterparts to strengthen the bilateral relationship and to jointly address regional and global challenges, Harf said.

Harf said the suspect is in custody and U.S. law enforcement is coordinating closely with the Korean National Police who have the lead on the investigation into the assault, adding that "we cannot speculate on a motive at this time."

The assailant was Kim Ki-jong, 55, head of a South Korean progressive cultural activity group. In July 2010, Kim received a suspended two-year jail term for throwing two pieces of concrete at the Japanese ambassador to Seoul.

While being arrested, Kim shouted his strong opposition to "war exercises," apparently indicating the South Korea-U.S. annual military exercises code-named "Key Resolve" and "Foal Eagle" that kicked off Monday. Endite