A former Korean wartime sex slave said Friday she will soon file a suit against the Japanese government with a U.S. court, seeking an apology and financial compensation for the atrocities done by the Japanese military during World War II.

Yoo Hee-nam, 87, will not only sue the Japanese government and Prime Minister Shinzo Abe but also seek damages from Japanese firms and a Japanese daily, said Ahn Shin-kwon, who heads House of Sharing in Gwangju, Gyeonggi Province, which houses a group of victims of sex slavery, quoting Yoo.

The total amount of compensation she is seeking is $20 million.

The firms she plans to sue are known for having mobilized millions of Koreans for forced labor during the war and have operations in the U.S.

The Japanese daily, Sankei Shimbun, will also be sued for calling former sex slaves "prostitutes" in its articles, Ahn said in a telephone conversation with Yonhap News Agency.

Yoo will try to convince the judges at a Californian district court that her sexual enslavement was a crime against humanity and Japan's repeated denial of it is rubbing salt into her wounds.

More than 200,000 women, mostly Koreans, were forced into sexual slavery by the Japanese soldiers during World War II, according to historians.

The suit will be lodged in the U.S. as a court battle there would deal a heavier blow to Japan than in South Korea, Ahn said.

The House of Sharing decided to start off with Yoo alone since a 2000 class-action suit against Japan in the U.S. ended in a loss.

"We considered the huge disappointment these former sex slaves would feel in case they filed a class-action suit and lost," Ahn said. "I hope we will win in the U.S. so Japan can finally make a formal apology and properly compensate these former sex slaves."

The South Korean government only has 238 sex slaves on file and of those, only 50 are still alive. (Yonhap)