SEOUL, June 23 -- South Korean victims of Japan's wartime sex slavery will sue Japanese Prime Minister Shinzo Abe in a U.S. federal court as the Abe cabinet has ignored calls for apology and compensation.

The victims, now in their 80s and 90s, held a press conference Tuesday at the House of Sharing, a shelter housing for the comfort women victims, or Korean women coerced into sex enslavement for Japanese military brothels during the World War II, according to local media reports. The shelter is located in Gwangju, Gyeonggi Province.

Ten South Korean women, forced into sex slavery for Japan's Imperial Army, and two bereaved families plan to file a damages claim lawsuit in July against Abe, the Japanese emperor, and Japan ' s war criminal enterprises, including Mitsubishi Heavy Industries,as well as Sankei Shimbun that belittled the victims as prostitute.

The lawsuit will be filed with the U.S. District Court in San Francisco, claiming 20 million U.S. dollars in damages.

Kim Hyung-jin, an attorney who will represent the victims in the U.S. court, was quoted by Yonhap News Agency as saying that the 20-million-dollar damages would not matter as Japan's sincere apology should be a priority.

Preparations necessary for the class action had already been completed two months earlier, but they were waiting for a sincere response from the Japanese government, Kim said.

The suit could be dropped if the Abe cabinet sincerely apologizes and actively seeks a way of resolving the issue, but given the old age of the victims, the Japanese government should respond to the call in July, Kim noted.

According to historians, at least 200,000 women, mostly Koreans, were forcibly or deceivably mobilized to military brothels for Japan's Imperial Army during the World War II.

Among 238 South Korean women who identified themselves as former sex slaves, only 50 are alive as five passed away in 2015 alone.

South Korean President Park Geun-hye attended the reception hosted Monday by the Japanese embassy in Seoul to mark the 50th anniversary of normalized diplomatic ties between the two countries.

Park said at the reception that the countries should move toward a new future, but she stressed the importance of curing historical scars left by the militaristic Japan during its colonial rule of the Korean Peninsula.