By Kelly Cohen • 2/6/16 11:38 AM

Rep. John Katko used the GOP's weekly radio address to urge the Obama administration to better enforce a new visa waiver law to stop terrorists from entering the country.

Congress tightened the rules of the visa waiver program in December. Under the adjusted rules, if someone has traveled to a country with serious terrorist activity after 2011, he or she must apply for a visa and is not eligible for a program that allows someone to travel to the United States for 60 days without one.

In the weekly Republican address, Katko, a freshman Republican from upstate New York, argued the Obama administration has put loopholes in the new provision, such as allowing journalists, humanitarian workers and people traveling to Iraq and Iran for legitimate business purposes to be granted exemptions. This puts Americans in danger, he said.

"In today's interconnected world, hundreds of thousands of people enter and leave our country every day," Katko said. "One of the greatest security challenges we face is eliminating vulnerabilities in our visa system so terrorists can't slip into our country."

Katko suggested that the Obama administration tweaked visa rules to avoid irritating Iran in the wake the nuclear agreement the United States and others cut with the Iranians last summer. Shortly after the new provision was signed into law, Iranian leaders said it would jeopardize the deal. Iran is the reason why the Obama administration has added exemptions into the provision, Katko argued.

"I am a former federal prosecutor, and I can tell you a law is only as good as how you enforce it," Katko said. "This is not a time to start lowering our guard. And we should not put Iran's feelings before America's security interests."

Congress has since requested a report from the Obama administration on who is receiving those visa waivers, Katko said. The lawmakers want the names and nationalities of the travelers and justification for the waiver.

"This law is a commonsense measure we need to keep us safe and we House Republicans will do all we can to make sure the administration enforces it in full," he said.