A judge has given the U.S. government six months to identify potentially thousands of children who were separated from their families at the Mexico border during President Donald Trump’s administration, the Associated Press reports. While U.S. District Judge Dana Sabraw issued the half-year deadline, he said he would consider an extension after the government said it could take up to two years to reunite the separated children, the AP reports. “It is important for all government actors to have a timeframe, a deadline,” Judge Sabraw said. “You tend to stand on it.” The administration will reportedly review 47,000 cases of unaccompanied children who were taken into custody between July 2017 and June 2018. While many of those separated during that period were reunited with their families, the Health and Human Services Department watchdog found thousands more children may have been separated since the summer of 2017—although the specific number is reportedly unknown.