WASHINGTON — Airlines are often to blame when passengers are pulled aside for additional screening for potential matches to names on a government terror watch list, the head of the Transportation Security Administration said Thursday.
"Some airlines have elected not to do what we would like to see them do, which is take care of the innocent passengers and not inconvenience them," said TSA administrator Kip Hawley.
He told the House Aviation Safety subcommittee that airlines have not made the investment needed for pre-screening passenger name lists.
But a representative of U.S. airlines faulted the TSA for not providing clear guidance earlier to resolve potential false matches.
"The airlines have been given assurances for more than four years that TSA would 'soon' be taking over responsibility for vetting passenger names against government watch lists," said Elizabeth Merida of the Air Transport Association.
"Facing a litany of other costly homeland security mandates, and in the midst of an ongoing economic crisis, airlines are understandably reluctant to spend millions more," she said.
'A business decision'
The federal government plans to take over early next year the task of checking passenger names against the government's list of people to be blocked from flights or subjected to more security screening. Hawley suggested that airlines are avoiding improvements to their own systems, knowing that TSA will soon assume the responsibility.
"We understand that's a business decision they have made," he said.
But he sharply criticized airlines for telling some passengers that they are subject to extra security because they are on a TSA watch list.
"That undercuts the credibility of the system. They are not on watch lists. They are being swept up in an airline filtering system that certainly catches the people we need to, but is also pulling in a lot of people who shouldn't be," Hawley said.
Passenger group sides with airlines
But a group representing passengers said instead of blaming the airlines, TSA should have taken over the pre-screening function long ago.
"Airline security should always have been a government responsibility, and deflecting criticism to the airlines is inappropriate," said David Stempler of the Air Travelers Association.
While government auditors have put the total number of names on the government's terror watch list at 400,000, TSA officials say its list of people designated for enhanced screening or prohibited from flying contains about 50,000. Of them, Hawley said, "a very small percentage" are U.S. citizens.
Since April, TSA has encouraged passengers who believe they are wrongly flagged for enhanced security to give their birth dates to airlines when making a reservation.
"By voluntarily providing this limited biographical data to an airline and verifying that information once at the ticket counter, travelers that were previously inconvenienced on every trip will now be able to check in online or at remote kiosks," TSA said in a statement.
"More airlines need to actively pursue this approach for all passengers," the statement said.
© 2013 NBCNews.com Reprints