The State Department issued close to 11 million temporary visas, which do not include permanent residency or “green cards,” during the 2024 fiscal year. The vast majority of these visas, 77 percent, were for business or tourism, while roughly 7 percent were issued to students or visiting academics and their families.

In practice, the process of revetting people who already hold a visa — potentially for years, in some cases — is likely to prove time-consuming and logistically complicated, officials have noted. The State Department has also introduced new measures, including the review of social media accounts for hostility toward the United States and antisemitism.

“We are gathering more information than ever,” said a senior State Department official, speaking on the condition of anonymity to brief the media. The official admitted it was likely that social media vetting would add more time to the review process.

The news alarmed some immigration experts, who said that visa holders are already subject to enhanced vetting when new information comes to light, including interactions with U.S. law enforcement agencies like arrests or convictions.

David J. Bier, the director of immigration policy at the Cato Institute, a libertarian think tank based in D.C., said it sounded like the administration wanted to “proactively conduct reviews of social media posts and revoke visas based not on conduct but speech.”

“I doubt that’s feasible for everyone, but I suspect that these reviews will be done in a discriminatory manner targeting immigrants with certain backgrounds and in certain visa categories or specific people they want an excuse to revoke,” Bier added.

Foreign students have become a focal point for the administration, which announced earlier this week that it had revoked more than 6,000 student visas for overstays and legal violations, including roughly 200 to 300 for what it described as “terrorism.”

The administration has also sought to revoke visas and deport people who took part in campus protests against the war in Gaza, claiming in some instances that these people had engaged in antisemitic behavior or shown support for designated terrorist groups such as Hamas and Hezbollah.

“There are thousands of people on visas in the United States who have exercised their freedom of speech who are not these people who we have revoked,” the senior official said.

In the statement, the State Department said that under President Donald Trump’s “commitment to protect U.S. national security and public safety,” it had revoked more than twice as many visas as during the same period last year, and roughly four times as many student visas.

Secretary of State Marco Rubio also announced Thursday that he will suspend the issuance of visas to commercial truck drivers after a fatal crash involving a semitruck that allegedly tried to make an unauthorized U-turn on a Florida highway. The truck driver is an Indian national who is in the country illegally, according to officials.