An amendment to grant the family residency was passed unanimously in the House Committee on Appropriations on Tuesday, according to Congresswoman Jaime Herrera Beutler, who introduced the amendment. But it would need a vote from the full House and the Senate to become law.
The amendment has been added to a controversial bill that includes money for US President Donald Trump's border wall and enhanced immigration enforcement, which could take a significant amount of time to be voted into law, if it is at all.
Charlie Gard is at the center of a global ethical argument over whether he should live or die. He was born in August with mitochondrial DNA depletion syndrome, a rare disease, and is being kept alive by life support.
Herrera Beutler -- whose own daughter was born with a rare and usually fatal disease but survived after treatment -- said that the committee had "an incredible opportunity" to help Charlie Gard.
"This amendment would speed up the process, cut through the bureaucratic red tape, and ease the path for Charlie to be able to receive medical treatment in the US that his parents and medical specialists believe is worth pursuing," she said in a statement
Charlie Gard's doctors have advised that the baby's life support be switched off, arguing he should be allowed to die in dignity, and several courts have upheld that decision
despite the boy's parents' appeals. The parents, Chris Gard and Connie Yates, want to take their son to the United States to undergo the experimental treatment.
CNN has reached out to the family spokesman and to the US embassy in London for comment.
US neurologist examines Charlie
The case of Charlie Gard has capture global attention, with Pope Francis and President Trump both weighing in on the issue. Trump had previously offered the baby and his family help from the US in a tweet, but did not elaborate on what that help might involve.
The British hospital where Charlie Gard is being kept is allowing Dr. Michio Hirano, a neurologist at New York's Columbia University Medical Center, to examine the baby this week in London.
Hirano is developing the experimental therapy, which has been used on at least one American patient with a similar but less severe mitochondrial disease. He specializes in myopathies and other neuromuscular diseases.
His evaluation of the baby will help inform a judge who is set to rule in the ongoing legal battle next week. The parents hope the court will overturn the most recent ruling that said the hospital could withdraw life support.
Mitochondrial DNA depletion syndrome is a progressive disease that causes muscle weakness and loss of motor skills, leaving those who have it unable to stand, walk, eat, talk and eventually breathe.