Editor’s Note: This video contains graphic content. U.S. ambassador to South Korea, Mark Lippert, was slashed in the face and hand by a Korean nationalist, police say. (Reuters)

North Korea hailed a slashing attack against the U.S. ambassador in Seoul as “deserved punishment” for U.S. participation in military exercises on the Korean Peninsula, adding possible new tensions Thursday amid the political fallout after the assault.

The brief dispatch by North Korea’s official news agency did not assert any claims of responsibility or suggest ties to the knife-wielding man who lunged at Ambassador Mark Lippert at a public event Wednesday, leaving the diplomat with wounds across his face and hands.

But the provocative message carried by the Korean Central News Agency reflected sharpened rhetoric and optics — including images of the North’s leader Kim Jong Un conferring with commanders — in response to the joint military drills that began earlier this week.

[N. Korea launches two missiles as U.S., South Korea begin military exercises]

The North’s state-run Korean Central News Agency called the attack a “knife shower of justice” and “deserved punishment for warmonger United States,” according to translations from news agencies including South Korea’s Yonhap.

There was no immediate comment from Washington on the North Korea statement.

But Secretary of State John F. Kerry, speaking in Saudi Arabia, denounced the “vicious attack” and said such violence will not sway U.S. policies.

“The United States of America will never be intimidated or deterred by threats, or by anyone who harms any American diplomat,” said Kerry, who spoke by phone earlier with Lippert.

“Doing well and in great spirits,” Lippert, a former assistant secretary of defense and adviser to President Obama, tweeted from the Seoul hospital where he was being treated after the gruesome knife attack that took place as he was sitting down for breakfast at a performing arts center in downtown Seoul.

The ambassador, who’s been in his post since last summer, said he, his wife, baby son and beloved basset hound Grigsby were all “deeply moved by the support.” The attack happened as Lippert was preparing to give a lecture about prospects for peace on the divided Korean Peninsula.

“Will be back ASAP to advance US-ROK alliance!,” Lippert tweeted, referring to the initials of the country’s official name, the Republic of South Korea.

Pictures and television reports released after the attack showed a stunned Lippert bleeding heavily from his head and hand at the Sejong Center for the Performing Arts, across the street from the U.S. embassy. Police said he was attacked with a 10-inch knife. Reports said the 55-year-old attacker yelled: “No war. The two Koreas should be unified.”

State Department spokeswoman Marie Harf, however, said a joint investigation is underway into the attack. “We cannot speculate on a motive at this time,” said Harf.

[The South Korean slasher accused of attacking U.S. Ambassador Mark Lippert]

Surgeon Jung Nam-sik of Yonsei University Hospital, speaking at a televised briefing, said 80 stitches were needed to repair Lippert’s facial wound, which was more than four inches long and one inch deep. The cut did not affect his nerves or salivary gland, the surgeon said. Lippert also suffered significant knife wounds to his left wrist while apparently struggling to push off his assailant.

The ambassador is expected to be able to use his hand after four weeks of treatment, but due to tendon damage, a more complete recovery will take longer because of the loss of sensation in his little finger, his doctors said.

“He’s as good as can be expected, his spirit is strong. He tends to soldier on, or as he said to me, sailor on,” said Kerry in a reference to Lippert’s Navy service.

Obama called Lippert to “wish him the very best for a speedy recovery,” National Security Council spokeswoman Bernadette Meehan said.

Police officials said the assailant, identified as Kim Ki-jong, was immediately apprehended. He is a member of the Korean Council for Reconciliation and Cooperation, which organized the seminar, police said.

Kim grabbed Lippert just as he was about to eat breakfast and slashed him about three times toward the right side of his face and his left wrist, reports said.

In July 2010, Kim threw a piece of concrete at the Japanese ambassador to South Korea and received a two-year suspended jail sentence, Yonhap reported.

Since arriving in Seoul last summer, Lippert has established himself as a down-to-earth, approachable ambassador. Unusually, he walks the short distance from his official residence to the embassy most days, greeting Koreans along the way.

He can also be seen early in the morning and at night walking his basset hound in the area of central Seoul where his residence, the embassy and the Sejong Center are all located. He has even set up a Twitter account for his hound Grigsby, @grigsbybasset, where he posts pictures of himself and the dog around Seoul.

Lippert and his wife, Robyn, had their first baby in Seoul earlier this year and gave the boy a Korean middle name — he’s called James William Sejun Lippert — which was widely reported in Korean news media.

But despite Lippert’s efforts at outreach, the American presence in Korea remains controversial. There are more than 25,000 U.S. troops in the South, guarding against the threat from North Korea, and some Koreans resent their continued presence 60 years after the end of the Korean War.

Murphy reported from Washington. Carol Morello in Riyadh, Saudi Arabia, Daniela Deane in London and Yoonjung Seo in Seoul dontributed to this report.

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