WASHINGTON (Reuters) - The U.S. Department of Homeland Security is considering tapping more than $230 million from the Transportation Security Administration to fund operations on the U.S.-Mexico border if Congress fails to approve additional funding, a person briefed on the matter said.

FILE PHOTO - A Transportation Security Administration (TSA) agent screens passengers at a security checkpoint at Hartsfield-Jackson Atlanta International Airport amid the partial federal government shutdown, in Atlanta, Georgia, U.S., January 18, 2019. REUTERS/Elijah Nouvelage

NBC News reported the plan earlier, citing documents of a contingency plan to fund $1.1 billion in southern border efforts.

The U.S. House of Representatives’ Appropriations Committee said on Tuesday it had not received any notification from DHS that it plans to shift existing funds.

NBC News said TSA could shift $50 million that had been set aside to buy advanced airport screening equipment and $64 million from a workers’ compensation fund for injured TSA employees.

The White House on May 1 asked Congress for $4.5 billion in emergency funds to address the rising number of people crossing the southwestern border with Mexico.

DHS spokesman Tyler Houlton said Tuesday in a statement the agency “is considering all options to address the humanitarian and security crisis at our southern border. We will continue to work with our workforce to find dynamic solutions and funding to address this very serious problem.”

Houlton said the agency was exploring “fiscal mechanisms that will ensure the safety and welfare of both our workforce and the migrant population, which is also reflected in the supplemental request submitted to Congress.”

The American Federation of Government Employees, the union representing TSA workers, said in a statement that shifting TSA funds would cause “another Trump administration manufactured ‘crisis.’”

“TSA is already underfunded and understaffed, and diverting its resources just as we enter the busiest travel season will be an operational disaster,” said the group’s president, J. David Cox Sr.

Last week, TSA confirmed it planned to redirect staff to the U.S. southern border to assist with immigration duties and migrant flows.

A TSA spokesman said the agency was looking for volunteers to support efforts at the border with Mexico, where the government has said it is grappling with record numbers of people.

TSA staff will include 175 law enforcement officials, including air marshals, and as many as 400 security staff drawn from six unnamed U.S. cities, but will not include airport screeners, CNN reported last week, citing two additional unnamed sources.

Officers apprehended nearly 99,000 people crossing the border with Mexico in April, the highest figure since 2007, the U.S. government reported earlier this month. More than two-thirds of those were children or people traveling as families.

Earlier this month, Customs and Border Protection (CBP) said it was deploying an additional 186 CBP officers to assist Border Patrol agents at sectors on the southwestern border, after earlier shifting more than 300 officers from airports, northern border checkpoints and other locations.