WASHINGTON — A federal judge on Thursday blocked President Donald Trump’s administration from immediately deporting Guatemalan migrant children who came to the U.S. alone back to their home country, the latest step in a court struggle over one of the most sensitive issues in Trump’s hard-line immigration agenda.

The decision by U.S. District Judge Timothy J. Kelly comes after the Republican administration’s Labor Day weekend attempt to remove Guatemalan migrant children who were living in government shelters and foster care.

There was already a temporary order in place preventing the removal of Guatemalan children. But that was set to expire Tuesday. Kelly, who was appointed by Trump, granted a preliminary injunction extends that temporary protection indefinitely, although the government can appeal.

There are also temporary restraining orders in separate cases in Arizona and Illinois, but those cases are much more narrow in the scope of children they cover.