Japanese government sources say Prime Minister Kishida Fumio decided just before the summit in South Korea what he would say regarding historical issues.
Kishida remarked on the wartime labor issue at a joint news conference with South Korean President Yoon Suk-yeol on Sunday. He said his "heart aches" when he thinks about the many people who endured suffering and sadness in a harsh environment during Japanese colonial rule.
The Kishida administration had been discussing ways to respond to the stance maintained by Yoon, who attaches importance to ties with Japan despite anti-Japan opinions that can be heard in his country.
The sources say that during the discussions, Kishida reaffirmed that his government takes the previous administrations' positions on historical recognitions.
He also proposed conveying a series of remarks on historical issues as his personal thoughts, including the expression his "heart aches."
Working-level arrangements were then made before finalizing the wording of his remarks by examining their consistency with past Cabinet responses to Diet questions, among other statements.
But the two countries' diplomatic authorities did not coordinate views on the remarks in advance. Kishida is believed to have told Yoon in person about his proposal at the outset of their talks.
One government official said the South Korean side appeared surprised. The official said it was Kishida's own decision to do whatever he can for future-oriented bilateral ties.