European travelers may find it hard to enter the United States in the future, according to recent reports. The announcement made by U.S. Department of Homeland Security director John Kelly on Wednesday in concern with the visa waiver program may have a large impact on European tourists who want to visit the U.S.

According to Travel and Leisure, the visa program that allows European nationals to travel to the States visa-free in less than 90 days will be subjected to heavy review. Reasons for these include threats of terrorism, as the number of Europeans joining militant groups such as ISIS, have increased in numbers.

But some analysts think this action is a response from the ongoing visa war between the US and the EU. Recently, the European Union has voted to suspend the privilege of visa-free travel for U.S. citizens.

Although the visa waiver program allows European nationals as well as other citizens of 38 countries to travel to the United States for 90 days without visa, they are still required to pass through the Electronic System for Travel Authorization (ESTA) online, a security measure designed to assess the risk of every foreigner entering the country. Some of the U.S.' closest allies are included in the program, but if certain restrictions arise, anonymity between nations may be unavoidable.

Also, it doesn't help that travelers around the world are not that keen on going to the U.S. for a holiday as it was before. Trump's two failed travel bans, which ignited religious racism, is one of the reasons travelers opted to travel to other destinations instead.

Tourism Economics already forecasted a 10.6 million decline in visitors in the U.S. for the next two years, according to The Telegraph. With that kind of number, the country's tourism economy would lose an estimated $18 billion and about 107,000 jobs.

European travelers have contributed a significant amount in the U.S. tourism economy, and all of this is the result of the visa waiver program. A bigger loss is already anticipated if the U.S. government decided to instill certain restrictions to the program. It would be "devastating", according to Chris Heywood, VP of global communications of the official New York City tourism board.