A federal judge on Friday extended his order protecting refugees in Minnesota who are lawfully in the U.S. from being arrested and deported.

U.S. District Judge John Tunheim granted a motion by advocates for refugees to convert a temporary restraining order that he issued in January into a more permanent preliminary injunction.

The order applies only in Minnesota. But the implications of a new national policy on refugees that the Department of Homeland Security announced Feb. 19 were a major part of the discussion at a hearing held by the judge the next day.

The Trump administration asserts it has the right to arrest potentially tens of thousands of refugees across the U.S. who entered the country legally but don't yet have green cards.

A new Homeland Security memo interprets immigration laws to say that refugees applying for green cards must return to federal custody one year after they were admitted to the U.S. so that their applications can be reviewed.

"This Court will not allow federal authorities to use a new and erroneous statutory interpretation to terrorize refugees who immigrated to this country under the promise that they would be welcomed and allowed to live in peace, far from the persecution they fled," Tunheim said.