SEOUL – The American ambassador to South Korea was injured in a politically motivated attack by a man wielding a razor on Thursday amid growing anti-U.S. tensions in the country.

Mark Lippert, the ambassador, was in stable condition with non-life threatening injuries at a Seoul hospital after he was attacked on his way to make a speech before a breakfast meeting, State Department officials and local police said.

The ambassador suffered cuts to his face and wrist.

Lippert was shown in news photos holding a cloth to his face as he walked to an emergency vehicle, and appeared to have been spattered with blood.

He was in stable condition at a nearby hospital, local news media reported.

Lippert, 42, is a close associate of President Obama, and formerly worked in the White House and Pentagon. He took up the ambassador's post last year.

The attacker was identified only as a man named Kim and was arrested. He is said to have shouted, "South and North Korea should be reunified."

Other reports said the man voiced opposition to the annual U.S.-South Korean military exercises called Key Resolve and Foal Eagle that are ongoing, police told reporters.

North Korea has voiced its opposition to the war games and said they were preparation for an attack on North Korea.

The attack comes amid growing anti-U.S. protests here over comments made last week by State Department official Wendy Sherman.

Sherman, undersecretary of state for political affairs, angered many South Koreans with comments that seemed to tell the country to give up hardline nationalist policies toward North Korea and to seek closer ties with its neighbor.

The South Korean government issued a formal diplomatic protest to the State Department over the remarks, sources said.

"Nationalist feelings can still be exploited, and it’s not hard for a political leader anywhere to earn cheap applause by vilifying a former enemy," Sherman said Friday in a speech at the Carnegie Endowment, a think tank.

"But such provocations produce paralysis, not progress," she said. "To move ahead, we have to see beyond what was to envision what might be. And in thinking about the possibilities, we don’t have to look far for a cautionary tale of a country that has allowed itself to be trapped by its own history."

The comments were interpreted by critics here as criticism of South Korean President Park Geun-hye’s hardline stance against North Korea.

Park is opposing the resumption of talks with North Korea because of Pyongyang’s refusal to discuss the dismantlement of its nuclear program.

Sherman is viewed by South Korean officials as pro-North Korea because of her 2000 visit to Pyongyang with then-Secretary of State Madeleine Albright.

Sherman’s remarks about nationalism, while not mentioning South Korea, also appeared designed to try to allay growing anti-Japanese sentiment in South Korea.

South Koreans have been demanding that Japan do more to atone for World War II-era human rights abuses, such as the so-called "comfort women" issue involving the use of South Korean women as sex slaves for the Japanese military.

China's communist government has been eager to exploit differences between Japan, South Korea, and the United States, according to analysts.

Marie Harf, deputy spokesperson for the U.S. State Department, said of the incident, "We strongly condemn this act of violence. The ambassador is being treated at a local hospital. His injuries are not life threatening."