NYPD Commissioner Bill Bratton called on Congress today to “start getting serious” about fixing the loophole that allows those on the U.S. terror watch list to legally purchase firearms in the United States.

Appearing on NBC’s "Meet the Press" alongside Homeland Security Secretary Jeh Johnson, Bratton said, "If Congress really wants to do something instead of just talking about something, help us out with that terrorist watch list, those thousands of people that can purchase firearms in this country. I’m more worried about them than I am about Syrian refugees."

He added, "If Congress really wants to do something to help the American law enforcement community and the American public, well let’s start getting serious about doing something that they can actually do something about.”

Secretary Johnson also said “there are ways Congress can help us” on the Visa Waiver Program, seen by some as a more of a weakness to U.S. security than refugees.

The Visa Waiver Program allows eligible citizens or nationals of certain countries — including France and Belgium — to enter the U.S. without a visa, for up to 90 days, after an online screening.

Asked if the United States should temporarily suspend the Visa Waiver Program, Johnson replied, “No, I would not do that at all. The Visa Waiver Program is very, very important to lawful trade, travel, commerce ... But there are security enhancements that we have made, and we should evaluate whether more is necessary, and I’m happy to have that conversation with our friends in Congress. They’re interested in this too.”

On the state of homeland security in the United States, Johnson said “We have no specific credible intelligence about a threat of the Paris-type directed at the homeland here. We are always concerned about potential copycat acts, home-born, homegrown, violent extremism of the types we’ve seen in recent months and years.”

As Brussels enters its second day on a security lockdown due to terrorist threats, Johnson explained, "We’re continually in touch with law enforcement, intelligence authorities in Western Europe, in Brussels, in Paris, and elsewhere and we monitor these things."

"We’re continuing to be vigilant, we’re continuing to monitor, reevaluate," he continued. "There’s also a role for the public to play too…which is if you see something, say something. That’s got to be more than a slogan.”

Bratton and Johnson had just finished observing a joint New York Police Department and Department of Homeland Security terrorism exercise on how authorities would deal with an active shooter situation on the subway.

The exercise was planned before the Paris attacks, Bratton said, but it had "certain Paris elements involved in it, including a scenario with an individual with a suicide vest."

"Beginning back with the Mumbai attacks many years ago, American policing and homeland security and federal agencies have constantly been adjusting with everything we’ve learned from these events, Paris, Mali," Bratton said. "We’re building all of that into these exercises going forward."