He said the Biden administration's refusal to let the press tour the holding facilities was "outrageous and hypocritical".
The new administration led by Harris and President Joe Biden is now being confronted with a border crisis engineered by the Democrats' soft rhetoric on immigration and aggressive pursuit of open border policies.
When Biden previously served as vice president, then-President Barack Obama tasked him with taking the lead on a variety of domestic and worldwide priorities, from shaping foreign policy on Iraq and Ukraine, to overseeing the implementation of the 2009 economic recovery act. But Harris' appointment places the former presidential candidate at the center of a politically fraught debate over how best to handle the border crisis. She claimed that the current administration was left with a challenging situation. The president identified several factors, including gang violence and natural disasters, that he said prompted migrants to flee their homes.
"I also look forward to working with members of Congress who I think share our perspective on the need to address root causes for the migration that we've been seeing", she said Thursday at the White House before she and Biden discussed immigration with the secretaries of homeland security and health and human services, as well as other advisers.
The cascade of immigration policies reversing President Donald Trump's strong immigration enforcement has provoked the flood of migrants flooding across the border.
"As the president has said, there are many factors that lead [migrants] to leave these countries", Harris said.
More than 15,000 unaccompanied migrant minors are in custody at federal facilities, according to recent reports.
Lawmakers from both parties have either visited border facilities or scheduled trips amid the mounting crisis.