TOKYO - Japan is set to unveil Friday a review of evidence that led to its landmark 1993 apology over wartime sex slavery, in a move that threatens to further chill ties with its neighbours.
In what observers say is a messy compromise that looks set to satisfy no-one, Prime Minster Shinzo Abe's government has said it will not reverse the apology, known as the Kono statement, which acknowledged official complicity in the practice.
Instead, the review has been examining how the decision to apologise was reached, and on what historical facts it was based.
Around 200,000 women, mainly from Korea, but also from China, Taiwan and Indonesia, were forced to work in brothels as "comfort women", serving imperial troops as Japan stomped across Asia before and during World War II.
While mainstream Japanese opinion holds that the wartime government was culpable, a small but vocal tranche of the political right - including Abe - continues to cast doubt, claiming the brothels were staffed by professional prostitutes.
The equivocation is a huge bugbear in Tokyo's relations with East Asia, and with South Korea in particular.
The conclusion of the probe by a five-member "verifying team" will be submitted to parliament later Friday, a parliament secretary told AFP, while local media said the government will disclose its findings shortly thereafter.
The move comes as South Korea holds a rare live-fire drill near islets at the centre of its territorial dispute with Japan, further raising the diplomatic temperature.
It also comes as Chinese state vessels sailed into disputed waters surrounding another set of islands, which are administered by Tokyo, but claimed by Beijing.
Japan's chief cabinet secretary Yoshihide Suga defended the review when quizzed about its possible impact on foreign relations.
"It is common for a democratic country that the prime minister sets up a verifying team and tells it to report to parliament," Suga told reporters.
It was unclear what would happen if Tokyo's review was at odds with the official apology, which followed testimony from 16 Korean women about their experiences.
Foreign Minister Fumio Kishida told reporters Friday he intends to "explain to South Korea... so that (the review) will be regarded as a forward-looking step for Japan-South Korea relations", Jiji Press reported.
The issue is a volatile one in South Korea, where feelings run high that Japan has never properly made amends for its warring, despite a 1965 treaty normalising ties that involved a multi-billion dollar settlement in regard to property and claims.
The inability of the two countries to bury the hatchet is a bane for Washington, which would dearly like its two major allies in the region to get along, especially in the face of an increasingly confident China.
While on a regional tour two months ago, US President Barack Obama blasted the comfort women system as a "terrible, egregious violation of human rights".