Emperor Akihito led an official memorial ceremony opened by Abe, which included a minute of silence.
The prime minister will also pay tribute with a visit to Chidorigafuchi, a national cemetery and memorial.
said Friday while he was remorseful for his country's actions in the war, future Japanese generations should not have to keep apologizing.
While he gave no new apology during a speech, he acknowledged previous ones, saying Japan must keep resolving to never again use force to settle international disputes.
"Japan has repeatedly expressed the feelings of deep remorse and heartfelt apology for its actions during the war," Abe said.
He said the country "engraved in our hearts" the suffering of Japan's Asian neighbors through its deeds, including China, South Korea, Indonesia and the Philippines.
But postwar generations now exceed 80% of Japan's population, he added.
"We must not let our children, grandchildren, and even further generations to come, who have nothing to do with that war, be predestined to apologize," Abe said.
"Still, even so, we Japanese, across generations, must squarely face the history of the past. We have the responsibility to inherit the past, in all humbleness, and pass it on to the future."
Decades of apologies
For decades, Japan has made repeated apologies, with some prime ministers personally expressing regrets for the nation's aggression in the war. Actions included using women from Korea, China and elsewhere in Asia as "comfort women," or sex slaves, for the Japanese military.
The lack of an apology Friday irritated some of its neighbors, including China, which Japan had invaded and occupied.
The statement "was a diluted one at best, thus marking only a crippled start to build trust among its neighbors," a column published Friday by China's state-run Xinhua news agency reads.
"Instead of offering an unambiguous apology, Abe's statement is rife with rhetorical twists ... dead giveaways of his deep-rooted historical revisionism, which has haunted Japan's neighborhood relations," the Xinhua article says.
Neighbors not satisfied
In South Korea, the spokesman for the country's ruling party noted that Abe's statement "did not include a direct apology."
"It's regrettable that he mentioned the comfort women issue in a rather indirect way," Kim Young-woo said. "Instead of pinpointing his ambiguous words, we'll continue to urge Japan to show sincere remorse and action for peace."
Abe hinted at the comfort women issue, saying Japan needed to remember the "women behind the battlefields whose honor and dignity were severely injured." He said Japan will help make this century one in which "women's human rights are not infringed upon."
Japan helped establish the Asian Women's Fund in 1995, which is supported by the government and provides assistance to former comfort women.
But Tokyo has resisted direct compensation to the victims, prompting some to say Japanese leaders are avoiding officially acknowledging what happened.
Only a few dozen of the women are still alive today.
South Korea's foreign ministry said its government was reviewing Abe's statement. South Koreans plan to hold anti-Japan protests in Seoul on Saturday, when the country is also celebrating the end of the war as marking freedom from Japanese oppression.
'An unpardonable mockery'
The reaction by North Korea's government, through its official news outlet KCNA, was more pointed.
"Japan is talking about future and responsibility and contribution in the international community without making an apology," North Korea's Foreign Ministry said through KCNA. "It is an unpardonable mockery of the Korean people and an act of deceiving the international community."
Complicating matters for Japan's neighbors is the island nation's apparently shifting military stance.
Japan has had a pacifist stance since the war, deploying troops only in humanitarian roles.
More active role for Japanese troops?
While Abe has distanced Japan from wars of aggression, he has backed legislation that would allow for a more active role for Japanese troops overseas, including involvement in the defense of its allies.
China and South Korea, invoking Japan's expansionist past, have expressed concern about the legislation.
Abe, 60, became Japan's first Prime Minister born after the end of World War II when he began a one-year term in 2006. His second stint in the office started in late 2012.