The restrictions, known as Title 42, and which will be lifted on May 11, allow US authorities to quickly expel non-Mexican migrants back to Mexico without the ability to claim asylum.
Biden, a Democrat running for re-election in 2024, has dealt with a record number of migrants caught crossing the US-Mexico border illegally since he took office in 2021.
Republicans have criticized Biden for undoing the hardline policies of former Republican President Donald Trump, the current favorite to be the party’s presidential nominee.
The troops would supplement the work of the US Border Patrol, but would not carry out any law enforcement operations, said the official, who spoke on condition of anonymity. Instead, they would carry out monitoring and data entry activities on the ground to support Border Patrol officers, the official added.
The force would add to the ongoing deployment of the National Guard.
Military troops have been used to help secure the border during previous presidential administrations, including Republican George W. Bush, Democrat Barack Obama and Trump, who have deployed thousands of active duty and National Guard soldiers.