South Korea expressed deep regret Tuesday after Japanese Prime Minister Shigeru Ishiba sent a ritual offering to a war shrine seen as symbolizing its militaristic past and its lawmakers paid their respects there.

Ishiba sent the offering to the Yasukuni Shrine honoring Japanese war dead, including 14 Class A criminals convicted by the Allies in international tribunals for their roles in World War II, on the occasion of the annual spring festival.

A bipartisan group of Japanese lawmakers also visited the shrine in person to pay their respects, according to Japanese media.

"We express deep disappointment and regret that responsible leaders in Japan have once again made offerings to or visited the Yasukuni Shrine," foreign ministry spokesperson Lee Jae-woong said in a commentary.

"We urge Japanese leaders to squarely face history and show through action humble reflection and genuine atonement for historical issues, and we once again emphasize that these will be the foundation for building a future-oriented bilateral relationship between the two countries," Lee said.

Sending an offering or visiting the shrine has drawn criticism from neighboring countries like South Korea and China, which view such actions as an attempt to glorify the country's militaristic past.

Japan invaded China during World War II and Korea was under Japan's colonial rule from 1910-45.

Since taking office in October last year, Ishiba has refrained from visiting the shrine. During the autumn festival last year, he only sent the Masakaki offering.

Former Japanese Prime Minister Shinzo Abe was the last Japanese leader to visit the shrine in December 2013.

Ishiba's decision to not visit the shrine was made in consideration of the improving ties with Seoul and Beijing, Japan's Kyodo news agency reported.

Yasukuni Shrine honors some 2.46 million Japanese war dead, many of whom are linked to the Pacific War that began in 1941 with Japan's attack on the U.S. naval base at Pearl Harbor.

The list on the shrine includes Gen. Hideki Tojo, who was executed in the tribunal for his leading role in the Pacific War.