(Reuters) - A U.S. judge on Thursday appeared open to ordering the government to find potentially thousands of additional children separated from their parents at the U.S.-Mexico border by the Trump administration, which could greatly expand the scope of a lawsuit challenging the separations.

U.S. District Judge Dana Sabraw in San Diego called a January report by an internal government watchdog that found the U.S. government had started implementing its policy of separating families months before it was announced "a very significant event."