A video of US border patrol agents charging at Haitian migrants with whips has created a massive outrage.
The White House has criticized the use of horse reins to threaten migrants after images circulated of a border guard on horseback charging at migrants near a riverside camp in Texas.
Videos showed mounted officers wearing cowboy hats blocking the migrants, and one officer swung a whip near a migrant's face.
"I don't think anyone seeing that footage would think it was acceptable or appropriate," White House spokeswoman Jen Psaki told reporters.
The camp under a bridge spanning the Rio Grande has become the latest flashpoint for U.S. authorities seeking to stem a flow of migrants fleeing gang violence, extreme poverty and natural disasters in their home countries.
US authorities are deporting thousands of Haitian migrants to their country.