Columbia University graduate student Mahmoud Khalil can be forced out of the country as a national security risk, an immigration judge in Louisiana ruled Friday after lawyers argued the legality of deporting the activist who participated in pro-Palestinian demonstrations.

Khalil, 30, was the first international student arrested in recent weeks amid an unprecedented crackdown by federal immigration authorities.

Khalil’s attorneys said they will keep fighting. They plan to appeal to the Board of Immigration Appeals. They can also pursue an asylum case on his behalf.