U.S. Sen. Kamala Harris (D) arrived Friday morning at a Southern California facility housing mothers who have been separated from their children at the U.S.-Mexico border.
Harris was expected to speak to the media outside of the Otay Mesa Detention Center with officials from the ACLU of San Diego and Imperial Counties after the visit.
Media was not permitted to join the tour of the facility.
A senior Trump administration official told the Associated Press about 500 of the more than 2,300 children separated from their families at the border have been reunited since May. It was unclear how many of the children were still being detained with their families.
President Donald Trump signed an executive order Wednesday ending forced separations of children from parents who are entering the U.S. at ports of entry.
However, it does not reverse the Trump administration's "zero-tolerance" policy calling for the criminal prosecution of all immigrants stopped on the southwest border.
Immigration attorneys NBC 7 spoke to Thursday say they are waiting to see what impact the president's actions will have on their clients' cases.
On Thursday, the House of Representatives rejected a bill that would have toughened border enforcement and funded the proposed border wall.
Republican leaders postponed final voting on what was billed as a compromise immigration package until next week as negotiators made a last-ditch push for support.
Harris, a member of the Senate Judiciary Committee and the Senate Homeland Security and Governmental Affairs Committee, called for the resignation of Homeland Security Kirstjen Nielsen earlier this week.
The Otay Mesa Detention Center, located on Calzada De La Fuente, is owned and operated by Core Civic, and its inmate population includes detainees of the U.S. Immigration and Customs Enforcement agency.