Nearly eight decades since the end of the war, the conflict remains a source of tension between Japan and its neighbours, particularly China and North and South Korea.
"Since the end of the war, Japan has consistently walked the path of a country that values peace," Suga said in a speech at a memorial ceremony in Tokyo. "We must never again repeat the devastation of war. We will continue to remain committed to this conviction."
His comments were little changed from those of his predecessor, Shinzo Abe, at last year's ceremony, and were echoed by Emperor Naruhito who expressed "deep remorse" for Japan's wartime past, as he has previously done.
Yet visits to the controversial Yasukuni shrine by members of Suga's cabinet as well as Abe on Sunday were likely to anger China and both Koreas. The shrine saw a constant stream of visitors from early morning, including families with children and people in military uniform, despite persistent rain and the recent spike in coronavirus cases.
Environmental Minister Shinjiro Koizumi and Education Minister Koichi Hagiuda both paid their respects. Suga is not expected to visit, although he did send a ritual offering through his secretary, the Sankei newspaper said.
Yasukuni honours the war dead, including 14 World War Two leaders convicted as "Class A" war criminals, making it a flashpoint for tension.
Koreans still chafe over Japanese rule from 1910 to 1945, while Chinese have bitter memories of Japan's invasion and brutal occupation of parts of China from 1931 to 1945.
South Korean President Moon Jae-in said his government remained open to dialogue with Japan to step up cooperation while seeking to resolve historical rows that have frayed bilateral ties.
"Like any other year, I sincerely offered my heartfelt condolences to those who sacrificed their lives in the previous war and renewed my pledge for everlasting peace," Hagiuda, the education minister, told reporters.
When asked about the opposition from South Korea and China to visits by ministers, he said it was natural to pay respects to those who sacrificed themselves for their country, adding he hoped for understanding from Japan's neighbours.
Abe visited Yasukuni as prime minister in 2013, sparking outrage from Beijing and Seoul and an expression of "disappointment" from the United States. He did not go again as prime minister, sending ritual offerings instead.
After visiting on Sunday the former prime minister, who is still a member of parliament, told reporters he paid his respect to the souls of the war dead. Reporting by Kiyoshi Takenaka; Editing by David Dolan and Kim Coghill