A San Francisco district judge has nullified a California law under which Korean and Chinese former prisoners had sued the Japanese companies.
The law had allowed victims of World War Two atrocities from anywhere in the world to sue for damages in California. The judge said the law infringes on the federal government's exclusive power over foreign affairs.
Judge Vaughn Walker also said Wednesday that Filipinos could not sue because their country was a signatory to the Treaty of Peace, which had also been signed by the United States and Japan.
He said allowing the suits to proceed could unsettle half a century of diplomacy between nations that signed the treaty in the 1950s.
Thousands of people from Korea, China, and the Philippines have been denied the right to pursue compensation lawsuits in U.S. courts.
Hundreds of thousands of Koreans were forcibly taken to Japan to power Japan's war machine under hazardous conditions during World War Two.