The Trump administration is barring Iranian investors and business people from entering or staying in the United States on certain types of visas.

In new regulations published in the Federal Register on Wednesday, the Department of Homeland Security said Iranians and their families are no longer eligible to apply for or extend what are known as E-1 and E-2 visas. The ban will take effect on Thursday, according to the notice from U.S. Citizenship and Immigration Services.

Those visas allow foreign “traders” and “substantial investors” in U.S. companies to live and work in the United States. CIS said the change is a result of the U.S. withdrawal last year from a 1955 treaty with Iran that had sought to promote commercial and economic ties between the countries.

Iranians in the United States on the affected visas will be required to leave the country when their visas expire, it said, although the new regulation does not bar Iranians from applying for or extending other types of visas for which they are eligible.

The number of Iranians in the U.S. on those types of visas was not immediately clear although it is believed to be relatively small. Out of more than 10 million U.S. non-immigrant visas issued annually, only about 48,000 E-visas are issued to people of from all nations.

(AP)