U.S. Sen. Bill Nelson says improving airport security won’t be easy.

U.S. Sen. Bill Nelson, D-Fla., said Wednesday that airport security has been improved recently, but last week’s shooting at Fort Lauderdale-Hollywood International Airport shows the issue is “a constant challenge.”

Nelson brought up the shootings at a Senate Commerce Committee confirmation hearing for Elaine Chao, President-elect Donald Trump’s nominee to serve as secretary of transportation.

The senator is the top Democrat on the Commerce Committee, which oversees the Federal Aviation Administration.

“Although the investigation remains ongoing, I expect all of us in the Congress to continue exploring ways to protect the traveling public in light of this tragic incident. And while we’ve made some progress in last year’s FAA bill to double the number of the VIPR teams, the dog teams, and bolster the screening of airport workers, this tragic shooting serves as reminder that our work to improve airport security remains a constant challenge,” Nelson said. VIPR refers to a Visible Intermodal Prevention and Response team.

“This year’s FAA reauthorization bill, that we will have to take up, could be a good place to start if more needs to be done to prevent similar tragedies from occurring, Nelson added.

Nelson’s staff, in a statement that included a text of his commerce committee remarks and a link to the comments on YouTube, described as a call “for an increase in airport security in the wake of Friday’s deadly shooting” at the airport.

In his remarks, Nelson said he wanted to express on behalf of the committee condolences to friends and loved ones of what he described as the “horrific shooting.” Nelson also praised “the heroic work that was undertaken by first responders and law enforcement personnel in responding.”

U.S. Rep. Debbie Wasserman Schultz, D-Weston — whose district includes the airport — said in a telephone interview Wednesday she would meet with leadership of the Transportation Security Administration this week to pursue security changes she raised within hours of the shootings on Friday.

“In response to this case, we need to narrowly focus on how to prevent tragedies like this one,” said Wasserman Schultz, who is a frequent traveler at the airport.

“Specifically, I definitely think we need to take a hard look at the unsecured areas of airports like baggage claim areas and review how we can better secure them,” Wasserman Schultz said. “We need to look at not just whether or not people should be able to check guns, but whether or not you should be able to carry ammunition along with that weapon.”

Wasserman Schultz said most of the changes she sees as necessary don’t need new legislation. “The TSA could just make them, but if legislation was involved and you couldn’t do that, then at the very least we need to look at how to reunite you with a firearm. It should be in a secure area away from other people that could come to harm.”

Sen. Bill Nelson on Wednesday.