A draft of Japanese Prime Minister Shinzo Abe's statement to mark the 70th anniversary of the end of World War II includes the word "apology", public broadcaster NHK reported Monday.
The closely-watched remarks - expected on Friday - will be heavily scrutinised by China and Korea, which dispute Tokyo's version of its wartime history and who are waiting to see if Abe repeats earlier apologies for Japan's militarism in the 20th century.
NHK said an original draft of Abe's statement included the words "apology" and "aggression".
Those words appear in a landmark 1995 statement by then premier Tomiichi Murayama, who expressed "deep remorse" and a "heartfelt apology" over Japan's actions.
The so-called Murayama Statement said Japan "through its colonial rule and aggression, caused tremendous damage and suffering to the people of many countries, particularly to those of Asian nations".
Also Monday, the right-leaning Sankei newspaper said Abe was likely to use the word "aggression", though not necessarily linking it to Japan's warring.
"It is likely that he will touch on [aggression] as a universally unforgivable act," the paper said.
Abe's statement is expected a day before August 15, the date Japan surrendered to the Allies in 1945.
The nationalist premier - who has been criticised by some for watering down Japan's past and trying to expand the role of Japan's military - said last week he would express "remorse" over the war.
He added that he would follow previous explicit Prime Ministerial apologies over the country's past "as a whole".
But Abe has repeatedly talked of the need for what he calls a "forward-looking attitude" that concentrates on the positive role Japan has played - and continues to play - in Asia since its surrender in 1945.
That has set alarm bells ringing in China and Korea, which suffered under Japan's imperial expansion and say any attempt to tone down explicit apologies made by previous leaders should be discouraged.
Last week, a government panel set up to advise on the wording of Abe's war statement condemned Japan's colonising the Korean peninsula from 1910 to 1945 and parts of China from 1931.
China says more than 20 million of its citizens died as a result of Japan's invasion, occupation and atrocities.
"The responsibilities of the Japanese government and military leaders from the 1930s and beyond are very serious indeed," said the panel composed mostly of academics and journalists.