A US judge has blocked expulsions of unaccompanied migrant children entering the US, halting a pandemic-era White House policy.
Judge Emmet Sullivan of the US DC District Court said that risk of Covid-19 could not be used to turn out the minors without due process.
Since March, the White House has used an emergency health declaration to remove migrants before they could asylum.
It affected thousands of minors.
In a two-page order, Judge Sullivan wrote that unaccompanied migrant children must be granted protections established by Congress, which gives some immigrants who enter the chance to apply for asylum, and bars migrant children from being deported.
Last spring, the Trump administration cited the onset of the coronavirus pandemic to override these protections, citing a law from the late 19th century which allows the government bar to people from entering to stop the spread of a communicable disease in the US.
Since mid-March, border officials have carried out expulsions for most migrants who do not have travel documents before they are able to meet with an immigration judge or speak with an asylum officer.
Agents have turned some migrants back immediately to Mexico, while keeping others in holding centres or hotels - instead of government-funded facilities meant to house children while they are placed with sponsors.
The policy has affected some 200,000 migrants in total since its implementation in March.
On Wednesday, Judge Sullivan ruled that the White House had acted outside the bounds set by Congress, writing that the public health law invoked by the administration does not authorise expulsions,
The administration has argued in court that this action was taken to prevent the infection of border agents and others in immigration custody. But critics have accused the administration of using the Covid-19 pandemic as a smokescreen to undermine humanitarian protections for migrants.
Lee Gelernt of the American Civil Liberties Union (ACLU), the lead lawyer for the case, called the ruling a "critical step" in stopping the Trump administration's attempt to "expel children under the thin guise of public health". According to the ACLU, more than 13,000 unaccompanied children have been expelled so far.
President-elect Joe Biden has promised to reverse many of the Trump administration's immigration policies but has not yet commented on the expulsions. According to CBS News, aides to Mr Biden have pledged to direct the US Centers for Disease Control and Prevention (CDC) and homeland security officials to review the order so that migrants are able to make asylum claims.
The Trump administration is likely to file an appeal to stop the order from taking effect.