A U.S. judge on Wednesday extended his order blocking federal authorities from deporting a detained Columbia University student, in a case that has become a flash point following a pledge by the administration of U.S. President Donald Trump to deport some pro-Palestinian college activists.

U.S. District Judge Jesse Furman had temporarily blocked Mahmoud Khalil's deportation earlier this week, and extended the prohibition Wednesday in a written order following a hearing in Manhattan federal court to allow himself more time to consider whether the arrest was unconstitutional.

The Department of Homeland Security (DHS) says Khalil, 30, is subject to deportation under a legal provision holding that migrants whose presence in the country are deemed by the U.S. Secretary of State to be incompatible with foreign policy may be removed, according to a DHS document.