South Korea's government plans to unveil on Tuesday a new monument as part of the first official day marking Japan's wartime use of 'comfort women', a euphemism for girls and women forced to work in Japan's wartime brothels.
The ceremonies marking the first "Memorial Day for Japanese Forces' Comfort Women Victims" threaten to exacerbate a sensitive diplomatic issue with Japan, South Korea's neighbour and a key ally of the United States in efforts to contain North Korea.
Japan has said the issue was resolved by a 2015 deal, struck by a previous, conservative South Korean administration, under which Japan apologised to the victims and provided 1 billion yen ($9.03 million) to a fund to support them.
But South Korean President Moon Jae-in's administration has spotlighted the emotionally-charged issue and has called for Japan to do more, despite backing down in January from formally renegotiating the deal.
In March, Moon described Japan's wartime use of comfort women as "crimes against humanity", with Japanese Chief Cabinet Secretary Yoshihide Suga calling Moon's remarks "extremely regrettable".
Tokyo has protested over other existing monuments in South Korea dedicated to comfort women, including one in front of the Japanese embassy in Seoul, as well as the move late last year to establish a day to remember comfort women/
A think-tank funded by the South Korean government-funded devoted to researching the issue also opened earlier this month.
The comfort women issue has been a regular cause for contention between Japan and neighbours China and North and South Korea since the war.
On Tuesday morning, over 50 activists joined a sit-in protest in front of Japan's de facto embassy in Taiwan's capital, Taipei, asking a formal apology and demanding monetary compensation for Taiwanese who were forced to work in its wartime brothels.
"The Japanese government should apologise," the crowd shouted, wearing black shirts with their faces covered by white masks.
Japan had colonised the Korean peninsula between 1910 and 1945 and occupied parts of China before and after the war.
Japan says the matter of compensation for the women was settled under a 1965 treaty. It says that in 2015, it agreed to provide the funds to help them heal "psychological wounds".
