Japanese Prime Minister Shinzo Abe has paid respects at a Tokyo war shrine that many of Japan's neighbors see as a symbol of its militaristic past.
The visit to the Yasukuni Shrine, the first by a sitting Japanese prime minister since 2006, was quickly condemned by South Korea and China, both victims of imperialist Japan's aggression.
Mr. Abe downplayed the political impact of the Thursday visit, saying it was not meant to hurt the feelings of Japan's neighbors, but was a sign of respect for his country's war dead.
"I also prayed for the resting of the souls of all the people whose lives were taken by war. Additionally, I vowed for a renunciation of war and I was emboldened to create an era where people's lives would not be engulfed and pained by the misery of war."
The Shinto shrine honors Japan's nearly 2.5 million war dead, including 14 convicted World War II war criminals.
China's foreign ministry spokesman Qin Gang immediately slammed Mr. Abe's visit as "absolutely unacceptable to the Chinese people" and demanded Tokyo "reflect on its history of aggression."
"The Chinese government expresses strong outrage and protest and solemnly condemns Japanese leaders ruthlessly trampling the feelings of the Chinese people and people of other war-affected Asian countries and bluntly challenging historical justice and human conscience."
The Xinhua news agency also said China will "make solemn representations" in Beijing and Tokyo on Thursday to protest the visit.
South Korea's minister of culture, sports and tourism, Yoo Jinryong, labeled the move as "anachronistic" and said it will hurt South Korea-Japan ties.
The U.S., a strong ally of Tokyo, said in a statement via its embassy in Japan that it is "disappointed" the country's leaders have undertaken an action that will "exacerbate tensions" with its neighbors.
Michael Cucek with the MIT Center for International Studies in Tokyo tells VOA the move likely sets back any efforts to improve relations between China and Japan.
"It's going to put everything at the bottom of the sea. It is absolutely a slap in the face to all of the people who have been working behind the scenes or formally trying to bring the governments of the region together. It's saying, 'I don't care.'"
Beijing says Tokyo has failed to atone for its brutal 1930s invasion of large parts of China. It views visits by Japanese leaders to Yasukuni as evidence it has not repented.
Prime Minister Abe, who is known for his hawkish views, has sent ritual offerings to the shrine. He also has said he regrets not visiting during his first term as prime minister, which ended in 2007.
His visit comes exactly one year after he ascended to Japan's top political post. It also came on the sensitive 120th anniversary of the birthday of Mao Zedong, who founded the People's Republic of China.
China-Japan ties have also worsened recently because of a bitter dispute over a group of uninhabited islands in the East China Sea.
Mr. Abe has accused China of using its rising military power to change the status quo of the Japan-controlled islands. He also plans to increase Japan's defense spending and revise its pacifist constitution to allow for what he calls a "proactive peace policy."