Duke University has issued a warning to its international students that they should not leave the United States unless absolutely necessary.

The statement was delivered on Friday by email to the university’s faculty, students, and staff, according to The Duke Chronicle.

Antwan Lofton, vice president of human resources and chief human resources officer, and Mary Pat McMahon, vice provost and vice president for student affairs, sent an email with a press release stating the “increased risks involved in re-entering the United States.”

Duke Visa Services issued the message on Friday, advising all members of the Duke international community to “avoid international travel unless essential.”

The warning came after stories of upsetting experiences at border crossings surfaced in recent weeks.

Duke students were urged to contact their Duke Visa Services liaison and, if they are citizens of one of the 43 countries under consideration by the Trump administration for a travel ban, to hire an immigration lawyer.

Duke Visa Services alerted passengers that “immigration officers are exercising strict entry procedures as part of the ‘maximum vetting’ policy of the current administration, and an increasing number of travelers are being referred to ‘secondary inspection’ where they may face additional questions and device searches.”

According to The Chronicle, university administrators also sent an email to international students Thursday afternoon urging them to “be mindful of their digital footprint and recognize its potential impact on their immigration status” following a federal order directing Department of Homeland Security officials to review visa holders’ social media activity for signs of antisemitism.

Furthermore, if the travel restriction on the 43 countries goes into place, Duke warned that students from one of them may be denied re-entry. Duke students were instructed to use their immigration student resource page and submit queries anonymously.

There have been numerous reports of US Customs and Border Protection officers checking people’s electronic devices.

“All travelers passing through the United States border are subject to CBP examination. On rare circumstances, CBP inspectors may search a traveler’s cell phone, computer, camera, or other electronic equipment during the inspection process,” according to a statement from US Customs and Border Protection.

According to the International Trade Administration, the total number of international visitors to the United States fell by 12% year on year in March, the sharpest reduction since the post-pandemic era in March 2021, as reported by The Financial Times.