Kamala Harris has 'grave concerns' after mounted border guards round up Haitian migrants

White House appears to hold Homeland Security Secretary Alejandro Mayorkas responsible after images emerged

Ms Harris called Homeland Security Secretary Alejandro Mayorkas to discuss the images showing agents whipping migrants. AP

US Vice President Kamala Harris has weighed in on a public relations crisis for the Biden administration after images and footage emerged showing mounted border patrol agents rounding up Haitian migrants as they attempted to cross the Rio Grande into Texas.

Ms Harris called Homeland Security Secretary Alejandro Mayorkas to discuss the images, taken at the US-Mexico border in Del Rio, the vice president’s spokeswoman Symone Sanders said on Wednesday.

In some pictures, border guards appear to lash at migrants using their horses' long leather reins.

The call could indicate the White House is holding Mr Mayorkas responsible as President Joe Biden's administration grapples with an influx of Haitians.

“The vice president raised her grave concerns about the mistreatment of Haitian migrants by border patrol agents on horses and the need of all [Customs and Border Protection] agents to treat people with dignity, humanely and consistent with our laws and our values,” a readout of the call said.

Nine members of the Congressional Black Caucus also visited the White House on Wednesday to discuss the situation in meetings with some of Mr Biden’s top advisers.

Mr Biden has already given Ms Harris the task of working with Guatemala, El Salvador and Honduras to stem the flow of migrants attempting to enter the US - many of whom are seeking asylum.

Last month’s 7.2-magnitude earthquake in Haiti and political upheaval following the assassination of former president Jovenel Moise have prompted an additional surge of Haitian migrants and asylum seekers to mass on the border Mexico in the hope of crossing into the US.

The readout of Ms Harris’s call with Mr Mayorkas noted that he shared her concern over the images and the vice president pledged to follow up with him “in the coming days".

Mr Mayokas has said that the Department of Homeland Security, which includes the Customs and Border Protection agency, is investigating the incident.

While testifying before Congress on Wednesday, he vowed to conduct the investigation “thoroughly but very quickly” in a matter of days and noted that he has informed the department’s inspector general.

The secretary said that the images “correctly and necessarily were met with our nation’s horror because they do not reflect who we are as a country, nor do they reflect who the United States Customs and Border Protection is".

“We have ensured that the individuals during the pendency of the investigation are not conducting law enforcement duties to interact with migrants but rather are conducting only administrative duties,” Mr Mayorkas said.

During the congressional hearing, several conservative Republicans laid into Mr Mayorkas, accusing him of not doing enough to secure the southern border.

But before the images surfaced, Mr Mayorkas had visited the area to urge Haitian migrants not to cross the border and said the US would have “no choice” but to expel them.

At the time, the Biden administration intended to deport the 12,000 Haitian migrants who had entered Del Rio and flights had already started to repatriate them.

After the images were released, however, the Biden administration appeared to quickly change course.

US officials told The Associated Press on Wednesday that the Biden administration is now releasing the Haitian migrants with notices to appear at an immigration office within the next two months.