New US visa rules could also cause problems for Americans visiting Europe

The Obama administration has tightened travel terms regarding Iran, Iraq, Syria and Sudan, under rules that will also make travel to the US harder for some Europeans.

The rules, which took effect on Thursday, create new visa requirements for dual nationals and anyone who has traveled to those countries in the last five years. Many Europeans enjoy visa-free travel to the US. Should they have dual citizenship or have traveled to Iran, Iraq, Syria or Sudan, they will require new permits.

The new rules, phased in under an anti-terrorism law passed in December, are designed to prevent people radicalized abroad from entering the US.

Iranian Americans have protested against the law, noting that it may require many of them to obtain visas because of Iran’s rules on citizenship and reciprocity provisions in the law.

Citizens of 38 countries, including the UK and France, can visit the US for up to 90 days without a visa – unless they are relevant dual nationals. The Department of Homeland Security said it will offer exemptions to the visa rule on a case-by-case basis, and listed potential exceptions for journalists, humanitarian workers, government officials and “legitimate business-related purposes”.

People who have listed dual nationality with one of the four countries will have their permits revoked, the DHS said. Some people have already been barred from entering the US.

On Tuesday a British-Iranian journalist working for the BBC was kept from boarding a plane when the US denied her visa waiver.

The DHS said such travelers can obtain a new visa after an interview at a US embassy or consulate.

Despite the thaw in relations between the US and Iran, the State Department still lists Iran with Sudan and Syria as a state sponsor of terrorism. The bill targets Iraq and Syria because Isis has carved out territory in both countries, and because foreign fighters fight with jihadi groups there.

Critics of the law argue that reciprocity agreements between nations will mean visa restrictions for some Americans traveling to Europe, and that the law undercuts Barack Obama’s diplomacy with Iran.

American lawmakers drafted new visa requirements in the aftermath of terror attacks in Paris and an apparently Isis-inspired shooting in San Bernardino, California. French authorities have identified the Paris shooters as mostly French and Belgian citizens who had traveled to fight in Syria.

The FBI has suggested that the California shooters, an American husband and his Pakistani wife, self-radicalized over several years, during which time they met in Saudi Arabia. The wife entered the US on a K-1 or “fiancee” visa in 2014.

The DHS did not immediately respond to questions about whether the US intends to change visa requirements for Saudi or Pakistani citizens, or for people who have traveled to those countries in recent years. Neither country is a member of the current waiver program.