WASHINGTON — The Obama administration Thursday revealed changes to a visa-waiver program that will make it harder for travelers to enter the United States from Europe if they have dual citizenship from Iran, Iraq, Sudan, or Syria, or have visited one of those countries in the past five years.
Those travelers will now have to go through the more-rigorous regular visa application process to enter the country.
The Department of Homeland Security, which announced the changes, said they would take place immediately.
The administration's plan would provide limited exemptions for individuals who have to travel to any of the four countries as diplomats or for military service. Additional exemptions could be applied for humanitarian reasons or for journalists.
About 38 countries, mostly in Europe, participate in the visa-waiver program, which allows their citizens to visit the United States without a visa on trips of 90 days or less. About 20 million tourists use the program each year.
The changes to the visa-waiver program come after the terrorist attacks in Paris on Nov. 13 that killed 130 people and injured 368. Because the attackers were all European citizens, some lawmakers and counterterrorism officials feared that terrorists could exploit the visa waiver program and travel to the United States to commit similar attacks.
Many members of Congress also worried that some of the travelers who could pose a security threat might overstay their visits. Two of the Sept. 11 hijackers, Satam al-Suqami and Nawaf Alhazmi, overstayed their visas.