A US judge has extended his order blocking federal authorities from deporting Mahmoud Khalil, a detained Columbia University student, in a case that has become a flashpoint of the Trump administration’s pledge to deport some pro-Palestinian college activists, Reuters reports.

US District Judge Jesse Furman had temporarily blocked Khalil’s deportation earlier this week, and extended the prohibition yesterday 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, aged 30 years, is subject to deportation under a legal provision holding that migrants whose presence in the country are deemed by the US Secretary of State to be incompatible with foreign policy may be removed, according to a document seen by Reuters.

“The Secretary of State has determined that your presence or activities in the United States would have serious adverse foreign policy consequences for the United States,” read the DHS document, dated March 9, ordering Khalil to appear before an immigration judge on March 27.

The document did not provide additional detail. The DHS did not immediately responded to requests for comment