BEIJING -- China and South Korea issued strong protests Tuesday over Japanese Prime Minister Junichiro Koizumi"s visit to the Yasukuni war shrine in Tokyo, warning he had further damaged regional relations.

"Regardless of the concern and opposition from the international community, neighboring Asian countries and the Japanese people, Koizumi insisted on visiting the Yasukuni shrine," China"s foreign ministry said in a statement.

"The Chinese government strongly protests such an act, which damages the basis of the Sino-Japanese political relationship and severely hurts the sentiments of people who have been victims of the Japanese aggression."

China"s foreign ministry said Koizumi"s visit "challenges international justice and tramples the conscience of mankind", adding it had undermined Japan"s image and interests.

In Seoul, Koizumi"s early morning visit to the Yasukuni shrine was met with similar outrage.

"We express deep disappointment and anger," the South Korean foreign ministry said in a statement, adding his visit had further strained bilateral ties and damaged regional cooperation.

"We strongly urge Japanese leaders in a responsible post not to hurt friendly relations between South Korea and Japan as well as peace and cooperation in Northeast Asia by visiting the Yasukuni shrine again," it said.

"Japan must build confidence with neighbors by facing up to history and putting its will into action if it really wants to contribute to regional peace and prosperity and to play a responsible role in the international community."

The Yasukuni war shrine honors 2.5 million war dead including 14 top war criminals from World War II.

China and South Korea view the shrine as a symbol of Tokyo"s past imperialism and have refused top-level encounters with Koizumi due to his shrine visits.

Koizumi"s visit came on August 15, the anniversary of Japan"s surrender in World War II, a conflict that cost an estimated 20 million Chinese lives.

The Japanese prime minister, who steps down next month, has visited the shrine once a year since taking office in 2001, each time infuriating China and South Korea. But he had never visited on the sensitive anniversary date.

Koizumi immediately rejected the criticism from China and South Korea and labeled them immature for consistently pressuring him not to go to the shrine.

"It is said, don"t do anything that annoys China or anything that annoys South Korea so Asian diplomacy will be in good shape. But I don"t think that"s the case," Koizumi told reporters.

"If Bush of the United States tells me not to go, would I stop? No, I would still go even then. But President Bush would not say anything so immature," said Koizumi, one of George W. Bush"s closest foreign allies.

Koizumi also insisted it was "appropriate" to honor the nation"s war dead by visiting the shrine on the anniversary of Japan"s World War II surrender.

"I made the visit to show respect and appreciation to those who offered their lives for the sake of the country and to their families. This feeling remains unchanged this year," he said.