WASHINGTON (AP) — The chief of the Homeland Security Department has told members of Congress that the government is "on track" to meet Thursday's court-ordered deadline of reuniting hundreds of migrant children with their families, lawmakers who met privately with her said.

Wednesday's assertion by Secretary Kirstjen Nielsen was greeted with open disbelief and anger, according to many of the roughly 20 members of the Congressional Hispanic Caucus — all Democrats — who attended. The private, hourlong meeting seemed to achieve little toward dousing lawmakers' criticism of how children taken from...