The White House said it was working with Mexico's government to resolve issues that led the Biden administration on Monday to close two rail crossings at the Texas-Mexico border used by increasing numbers of migrants to enter the US.

Dozens of major US agricultural groups on Wednesday urged the US to reopen the crossings, saying the closures of the railroad trade routes were causing steep export losses to US growers.

The farm groups said the US Customs and Border Protection agency could reopen the rail bridges with as few as five employees per crossing, challenging the agency's rationale for shutting down the train routes.

A White House spokesperson said later on Wednesday that the US was "working closely with the Mexican government in an attempt to resolve this issue, while surging personnel to the region."

"We are communicating regularly with industry leaders to ensure we are assessing and mitigating the impacts of these temporary closures," the spokesperson said.

The White House also repeated that US Homeland Security Department officials shut down the two crossings to "stop a large movement of migrants coming by rail and to protect the health and safety of its personnel."