The U.S. government is likely to announce Thursday its plan for new visa requirements for European travelers who have dual citizenship of Iran, Sudan, Iraq or Syria or have visited these countries in the last five years, a report by the Associated Press (AP) said, citing officials and congressional aides. The new rule comes as U.S. officials try to prevent Europeans, who have fought alongside the Islamic State group, from entering the country.

The AP report said that the Department of Homeland Security will sketch out a plan on how to implement the new rule. The law, which was passed by the Congress in December, affects only a minority of Europeans but countries whose citizens have access to visa-free travel to the U.S. have expressed concern. Subsequently, Iran also blamed the U.S. of violating the nuclear accord by penalizing legitimate business travel to Iran.

The biggest concern, however, remains for group of individuals who could be exempted by law and allowed to travel to the U.S. under the Visa Waiver Program. The AP report cited a congressional aide who said that the administration will put in place exemptions for those who traveled to any of the four countries for government work, or for the United Nations. Those who visited the countries for humanitarian work or for journalistic reasons will also be exempted.

The aide also referred to Iran’s concerns and said that those traveling for legitimate business will not be punished under the new rule. However, no waivers were reportedly made for dual citizens. Also, it was not clear if the latest rules would be supported by the Congress, the AP reported.

The move comes after the White House tightened security for the Visa Waiver Program in November, following the terror attacks in Paris that claimed 130 lives. The changes allowed security officials to more closely screen travelers from 38 countries whose citizens were allowed to visit the U.S. without obtaining a visa.