President Joe Biden found videos of tactics used by Border Patrol agents on horseback against Haitian migrants at the Texas border "horrific and horrible," White House press secretary Jen Psaki said Tuesday.
"I don't know anyone who could watch that video and not have that emotion," Psaki said on "CBS Mornings."
The videos from outlets including Reuters and Al Jazeera appear to show a mounted Border Patrol agent snap his horse's reins in the direction of a migrant who then stumbles back into the Rio Grande near Del Rio, Texas.
However, it is unclear from the video if the agent was using his reins to control the horse and prevent it from falling into the water.
At the United Nations Tuesday, reporters asked Biden for his reaction to the images of U.S. Border Patrol agents confronting migrants near where thousands of Haitians are camped under a bridge.
“We’ll get it under control,” he said.
The video comes as more than 14,000 Haitian migrants surged over the border in Del Rio in the past week.
Psaki said that the videos were inconsistent with the values of the administration, and vowed to pursue an investigation, a sentiment shared by Secretary of Homeland Security Alejandro Mayorkas in a statement Monday.
"I think it's important for people to know this is not who we are," Psaki said. "That's not who the Biden-Harris administration is, and we're going to absolutely pursue that investigation and get to the bottom of what happened here."
Speaking to reporters in Washington, Vice President Kamala Harris also commented for the first time on the images, calling the treatment “horrible” and saying she supported an investigation backed by Mayorkas.
"What I saw depicted about those individuals on horseback treating human beings the way they were, was horrible," Harris said. “And I fully support what is happening right now, which is a thorough investigation into exactly what is going on there. But human beings should never be treated that way. And I'm deeply troubled about it, and I'll also be talking to Secretary Mayorkas today about it."
On the Senate floor Tuesday, Majority Leader Chuck Schumer called on the Biden administration to halt expulsions of Haitian asylum seekers under Title 42, calling the images of immigrants being rounded up by horseback "stomach-turning."
"I urge President Biden to put a stop to these expulsions and to end this title 42 policy at our southern border," Schumer said. "We cannot continue these hateful and xenophobic Trump policies that disregard our refugee laws."
At the end of a Capitol Hill hearing Tuesday, Mayorkas welcomed questions about the images. He outlined the steps announced by the Homeland Security Department Monday night, including the request for an independent federal investigation as well as an internal review.
"I was horrified to see the images, and we look forward to learning the facts that are produced from the investigation and we will take actions that those facts compel," he said. "We do not tolerate any mistreatment or abuse of a migrant. Period."
The U.S. Customs and Border Protection Office of Professional Responsibility began investigating the incident Monday night. A spokesperson for the agency said that it "does not tolerate the abuse of migrants in our custody" and takes the allegations seriously.
"The footage is extremely troubling and the facts learned from the full investigation, which will be conducted swiftly, will define the appropriate disciplinary actions to be taken," the spokesperson said.
CBP has not said whether it will continue to use agents on horse patrol in Del Rio or elsewhere along the border while it investigates.
During a press briefing Monday, Psaki said that the White House needed more context for the images, but said that even without "full context" she didn't think it would be acceptable action.
"We just saw this footage, it's horrible to watch. I just have to get more information on it," Psaki said. "I don't have more information on it. I have also seen the video. I can't imagine what the scenario is where that would be appropriate."
Mayorkas said the administration plans to empty out the Del Rio encampment within the next 10 days, saying the number of migrants there was now "well under ten thousand."
"We are hoping that what we are doing now serves as a deterrent," Mayorkas said, noting some in Mexico have turned away from the border recently.
ABC News' Ben Gittleson, Justin Gomez, Luke Barr and Allison Pecorin contributed to this report.