In his first interview since taking over as TSA chief July 1, John Pistole told USA Today some terrorists view mass transit and railways as easier targets than passenger planes.
"Given the list of threats on subways and rails over the last six years, going on seven years, we know that some terrorist groups see rail and subways as being more vulnerable because there's not the type of screening that you find in aviation," Pistole said.
"From my perspective, that is an equally important threat area."
Pistole, 54, spent 26 years at the FBI, where he was deputy director before coming to TSA. He said he wants TSA workers, including 47,000 screeners at U.S. airports, to operate as a "national-security, counterterrorism organization fully integrated into U.S. government efforts."
Lawmakers including Rep. Bennie Thompson, D-Miss., the House Homeland Security Committee chairman, have urged the TSA to spend more on mass-transit security.
Thompson, who met with Pistole Thursday, said the new TSA chief agreed. Thompson said he was "impressed with Pistole's knowledge of security" and his experience at the FBI as a manager. "From that, I am confident he won't pass on making difficult decisions," Thompson said.
Pistole has a wide range of security and terrorism experience and was heavily involved in investigations into the Christmas Day attempt to blow up a U.S. passenger jet over Detroit and the attempted car bombing in New York's Times Square in May.
Pistole is President Barack Obama's first TSA chief. Obama's first two nominees withdrew during the confirmation process.