GRAPHIC IMAGES: Horrific moment U.S. Ambassador to South Korea was slashed in the face by knife-wielding activist in Seoul, leaving him with 80 stitches

Husband and father: Ambassador Lippert's wife Robyn gave birth to their son James William Sejun Lippert in South Korea in January. Sejun is a Korean name

A horrific image has emerged showing the gaping wound inflicted on the U.S. Ambassador to South Korea's face after a furious activist slashed it open with a knife.

Mark Lippert needed 80 stitches to fix the damage caused by the attack in broad daylight as he attended a breakfast meeting Thursday morning in Seoul.

Korean media reports that someone yelled 'North Korea and South Korea should be unified' and 'no to war training!' before the bloodied Ambassador was seen leaving the Sejong performing-arts centre around 7:40am local time.

The attacker appears to have slashed Lippert on the right cheek and left wrist. The State Department says the injuries are non-life-threatening and that Lippert is in stable condition after undergoing surgery at a nearby hospital.

'It is regrettable that an incident like this took place,' South Korean Prime Minister Lee Wan-koo said after the attack.

 A 55-year-old 'pro-North Korea activist' name Kim Ki-jong was arrested immediately after the attack, and video shows the suspect in a salmon colored jacket being wrestled to the ground. 

Police say the man was a member of the pro-Korean reunification group that organized the breakfast meeting on Thursday. 

Just before the ambassador was about to give a speech, Kim reportedly pushed Lippert from behind onto a table and started slashing him with a 10-inch knife, police confirmed. Kim injured his foot in the fight.  

Chung Nam-sick of Severance Hospial says it took 80 stitches to close the 4-inches long and 1-inch deep wond to Ambassador Lippert's face.

While there was no nerve or gland damage from the face gash, the knife apparently cut nerves connected to Lippert's little finger and thumb when Kim struck his left hand.

Nam-sik says Lippert will remain at the hospital for three to four days and could experience sensory issues with his left hand for several months.

It appears this isn't the first time Kim has attacked a foreign official. 

Yonhap reports that Kim was handed a three-year suspended prison sentence in 2010 for hurling a slab of concrete at the Japanese ambassador. 

He was allegedly protesting the Japanese claim to the Dokdo Islands - a small chain in the Sea of Japan that both countries claim sovereignty over. 

The attack has drawn questions about whether Kim acted alone, or was part of a larger conspiracy hatched perhaps by rival North Korea.

Kim has been described in the Korea Times as a 'pro-North Korea activist' and South Korean intelligence officials revealed to Yonhap the fact that Kim traveled to North Korea six times between 2006 and 2007.

In 2011, Kim allegedly tried to get a memorial erected to the late North Korean leader Kim Jong-il in the middle of Seoul, the year the so-called Supreme Leader died.

However, former FBI Assistant Director Tom Fuentes expressed skepticism of North Korean involvement. 

'I can't imagine that this is a hired assassin,' Fuentes commented on CNN. 

In addition to his strong feelings about Korean reunification, Kim also reportedly tried to set himself on fire in 2007 in an attempt to get the government to investigate a 1988 rape at his office. 

On his Twitter profile, Lippert has posted several pictures of him walking around the city relatively alone with his basset hound. 

South Korean Prime Minster Lee Wan-koo promised to beef up security for foreign emissaries following the attack. While the U.S. provides some security for their diplomats abroad, protection is customarily the responsibility of the host country.  

'It is regrettable that an incident like this took place,' Lee Wan-koo said following the attack, adding that he has ordered the best hospital care for Lippert. 

Lippert, 42, became ambassador last year and has been mostly popular during his time in Seoul. His wife Robyn gave birth to a boy in January and the proud-parents gave him a Korean middle name to mark his birthplace.

Lippert was formerly the U.S. Assistant Secretary Defense for Asian affairs and was a key adviser during President Obama's 2008 campaign. He is also a Navy reservist.

Following the attack, Mr Obama called Ambassador Lippert to check in on his condition. 

'The President called U.S. Ambassador to the Republic of Korea, Mark Lippert, to tell him that he and his wife Robyn are in his thoughts and prayers, and to wish him the very best for a speedy recovery,' a White House spokesman said in a statement. 

The attack on Lippert comes more than two years after Christopher Stevens, U.S. Ambassador to Libya, was assassinated in an attack on his residence in Benghazi.  

The State Department initially said the attack was the result of an impromptu protest to an anti-Muslim film. It was later revealed that the raid was actually planned and carried out by Islamist militants to mark the anniversary of the September 11, 2012 terrorist attacks on the Twin Towers and Pentagon.