The State Department said Thursday that it’s reviewing the records of more than 55 million foreigners who hold valid U.S. visas for potential revocation or deportable violations of immigration rules.

In a written answer to a question posed by The Associated Press, the department said that all U.S. visa holders are subject to “continuous vetting” with an eye toward any indication that they could be ineligible for the document.

Should such information be found, the visa will be revoked and, if the visa holder is in the United States, he or she would then be subject to deportation.

The department said it was looking for indicators of ineligibility including visa overstays, criminal activity, threats to public safety, engaging in any form of terrorist activity, or providing support to a terrorist organization.

“We review all available information as part of our vetting, including law enforcement or immigration records or any other information that comes to light after visa issuance indicating a potential ineligibility,” the department said.