The program currently allows passport holders of 38 countries to visit the U.S. for short stays without a visa.
President Donald Trump's administration is cracking down on the visa waiver program that allows citizens of 38 countries to travel to the U.S. for less than 90 days without needing to apply for a visa.
The new rules are aimed at heightening security both in airports of departure and upon arrival to detect potential homeland security threats. The administration is also seeking to ensure that all visitors depart the U.S. after their 90 days are up.
The U.S. will require countries to screen their travelers for potential threats by using U.S. counterterrorism data in addition to their own national data. Participating countries will also need to screen their airport workers for potential threats, according to a press release from the Department of Homeland Security (DHS).
In order to curb the number of people who overstay their allotted 90 days, the department will require that countries which have a 2 percent or greater rate of overstaying must initiate public information campaigns to educate their citizens about travel rules. Those four countries are Hungary, Portugal, Greece, and San Marino.
Around 20 million people per year visit the U.S. through the visa waiver program, allowing for both personal and business travel. In order to participate in the program, countries must already meet a high level of security readiness, one which was heightened following the attacks on 9/11. The majority of countries in the program are European.
Travelers who participate in the program will likely not notice a difference when taking a trip to the U.S., as much of the changes concern intelligence sharing as opposed to airport screening.
DHS denied that any specific event or piece of intelligence had prompted the changes.
"The United States faces an adaptive and agile enemy, as terrorists continue to explore ways to reach our country and to direct, enable and inspire attacks against us," said Homeland Security Secretary Kirstjen Nielsen. "It's critically important we stay ahead of these threats by improving our security posture."
A number of high profile terror attacks on European soil in the past five years might have prompted the change, according to one policy analyst.
“There still is a real concern over a lack of European border security,” Edward Alden, an expert on immigration at the Council for Foreign relations, told Travel + Leisure.
Freedom of movement is a core component of the European Union, and accords like the Schengen Agreement allow people to move throughout most of continental Europe without passport checks.
However, intelligence sharing and cooperation between these European countries and the U.S. is very strong, according to Alden, who called the latest measures “just a further enhancement.”