SEOUL -- South Korea on Tuesday expressed deep regret over Japanese Prime Minister Shigeru Ishiba's ritual offering to the notorious war-linked Yasukuni Shrine on the occasion of its annual spring festival.

The South Korean foreign ministry said in a statement that the government expresses deep disappointment and regret over the fact that Japan's responsible leaders once again sent offerings to and paid respects at the Yasukuni Shrine which glorifies Japan's war of aggression and enshrines war criminals.

South Korea urges the Japanese leaders to squarely face history and demonstrate through action their humble reflection and sincere remorse for Japan's history, said the statement, stressing that these would be an important foundation for the future-oriented development of South Korea-Japan relations based on mutual trust.

On Monday, Ishiba sent the ritual tree, called "masakaki," on the first day of the three-day ceremony at the war-linked shrine.

The Yasukuni Shrine in central Tokyo honors 14 convicted Class-A Japanese war criminals from World War II, including Hideki Tojo. It has long been a source of diplomatic friction for Japan and its neighbors.

For a long time, some Japanese politicians and members of parliament have insisted on visiting the shrine, which has been strongly opposed by many peace-loving people at home and abroad.