In a bid to keep ISIS supporters out, the US has tightened its visa waiver programme for nationals of certain countries, making it harder for them to enter America if they had dual citizenship of Iran, Iraq, Sudan or Syria or visited one of them in the last five years.

Citizens of the 38 countries, which are part of the visa waiver programme, would no longer be able to get an automatic entry into the United States if they have visited these four countries – Iran, Iraq, Sudan and Syria – after March 2011, the State Department said.

The State Department said any traveller who receives notification that they are no longer eligible to travel under the Visa Waiver Programme (VWP) are still eligible to travel to the US with a valid nonimmigrant visa issued by a US embassy or consulate.

"Such travellers will be required to appear for an interview and obtain a visa in their passports at a US embassy or consulate before travelling to the United States," the State Department said.

White House Press Secretary Josh Earnest said the goal here is to improve and tighten the screening measures that were in place for those individuals that had recently travelled to countries that were the state sponsor of terrorism.

"We want to make sure that we are doing everything that is necessary to keep the country safe. That is the top priority. But we also don't want to unnecessarily disadvantage American businesses that are trying to do business overseas, because ultimately that's good for our economy, it's good for creating jobs here in the United States," he said in response to a question.

"The goal here is to, number one, make sure that the country is safe and that we have in place appropriate screening for those individuals that have recently travelled to the nations of Iran, Iraq, Sudan and Syria," Earnest said.

The restrictions that have been put in place do not prevent individuals from travelling to the United States.

"What they do is they subject individuals that have recently travelled to these countries to more screening. And that's an important thing for people to understand," he said.
Currently, the Visa Waiver Programme allows citizens of participating countries to travel to the US without obtaining a visa. Thirty-one of the 38 countries in the programme are European nations, with some Asian countries included as well, according to the State Department.

The adjustment was mandated by legislation passed in the wake of November's deadly ISIS-linked terrorist attacks in Paris and a deadly shooting in California in December.

The vast majority of foreign fighters who have joined ISIS or other terrorist groups and then returned to the West have gone to Iraq and Syria. Syria, Iran and Sudan are also designated as state sponsors of terrorism, according to the State Department.