One U.S. citizen reportedly suffered minor injuries in the Istanbul airport attack this week which killed until this moment 44 people and injured 256, U.S. Homeland Security Secretary Jeh Johnson said on Thursday.

Johnson said Tuesday’s attack bore the “hallmark” of terrorist group ISIS and that Americans should expect to see more state and federal law enforcement officials at airports, train stations and other transit hubs around the country over the July Fourth holiday weekend.

“We will not shortcut aviation security in response to increased travel volume and longer wait times,” Johnson told the committee.
Johnson also said he has seen foreign militant groups disseminate literature about ways to obtain guns easily under U.S. laws, such as the “gun show loophole,” this week.

He said he supported “sensible” legislative proposals to tighten gun control such as universal background checks.

“Those determined to commit terrorist attacks on our homeland are taking advantage” of the United States’ comparatively light gun controls, he told the committee.

“So I think it’s a matter of homeland security that we address this.”
Johnson also weighed in on the recent U.S. Supreme Court decision to block President Barack Obama’s plan to spare millions of illegal immigrants from deportation.

“We’re disappointed in the court decision, and at some point, it’s going to be up to Congress to wrestle with this issue. We have to account for these people. They’re here and they’re not going away,” he told the committee.

Lawmakers from both parties grilled Johnson over violent crimes carried out by illegal immigrants in the United States, which committee Chairman Charles Grassley, a Republican from Iowa, said were the result of “lax immigration enforcement” and sanctuary-granting policies.

Johnson was also criticized for being too aggressive in deporting immigrants by protesters from United We Dream, an immigrant advocacy organization.