Updated at 2:30 p.m. ET
The acting commissioner of U.S. Customs and Border Protection plans to step down in the coming weeks, according to two agency officials.
John Sanders is expected to make his resignation effective July 5, according to the officials, who spoke to NPR on condition of anonymity because an official announcement had not been made to agency employees.
Sanders has held the post for just over two months, after President Trump tapped his predecessor, Kevin McAleenan, to be acting chief of Homeland Security.
Customs and Border Protection has come under fire in recent days amid revelations that nearly 300 migrant children — from infants to 17-year-olds — had been detained in a remote Border Patrol station in West Texas without adequate food, water and sanitation.
All but 30 of the children were transferred out of the center in Clint, Texas, after revelations last week that they were being held in squalid conditions.
Rep. Veronica Escobar, a Democrat who represents the area, said Monday that the children were supposed to have been moved to other facilities. But a CBP official confirmed Tuesday that 100 of those children have been moved back to the same Border Patrol station because there wasn't room in child shelters run by Health and Human Services.
Under the Flores settlement, a 1997 agreement that dictates how the government is supposed to treat detained underage migrants, children held by the Border Patrol are supposed to be transferred into the care of the Office of Refugee Resettlement within 72 hours. But many of the children were held for weeks at the Clint facility, which CBP says is not bound to the 72-hour limit because it is an emergency shelter.
The White House has been urging Congress to approve a supplemental budget request since last month, saying it will run out of money to house and care for migrants by the end of the month.
That additional funding, according to HHS spokeswoman Evelyn Stauffer, would go toward increasing "shelter capacity in order to meet the needs of the minors in our custody while ORR works to find sponsors, usually family members, for the children."
The House is expected to vote Tuesday on a supplemental spending measure that would send money to agencies working to address the needs of migrants arriving at the U.S. border with Mexico.
As NPR's Kelsey Snell reported, last-minute requirements were added to the $4.5 billion legislation that would obligate CBP to establish hygiene and medical standards for children and a 90-day limit on keeping kids in temporary emergency shelters.