The US is tightening its screening of international students, its first security change in response to the Boston Marathon bombings last month.
The move comes after a student from Kazakhstan – who did not have a valid visa – was accused by police of hiding evidence for one of the bomb suspects.
The Department of Homeland Security has ordered border agents to automatically check the visa status of every student.
Azamat Tazhayakov had returned to the US despite being dismissed from school.
The 19-year-old appeared in court on Wednesday, accused of helping to throw out a backpack belonging to his friend, Boston bombing suspect Dzhokhar Tsarnaev. No second check
Mr Tazhayakov’s student visa had been terminated by the time he arrived in New York on 20 January, following his academic dismissal from the University of Massachusetts-Dartmouth on 4 January.
The Department of Homeland Security will “effective immediately” verify that every international student visa is valid, according to an internal memo obtained by the Associated Press news agency on Friday.
Under the new procedures, border agents will verify a student’s visa status before the person arrives in the US, using information provided in flight manifests.
If that information is unavailable, they will manually check the visa status through a US database.
Beforehand, border agents would only verify a student’s status in a database, the Student and Exchange Visitor Information System, when the person was referred to a second officer for additional inspection or questioning.