The Trump administration has given immigration officers broader powers to detain legal refugees awaiting a green card to ensure they are "re-vetted," an apparent expansion of the president's wide-ranging crackdown on legal and illegal immigration, according to a government memo.

The U.S. Department of Homeland Security, in a memo dated February 18 and submitted in a federal court filing, said refugees must return to government custody for "inspection and examination" a year after their admission into the United States.