By Patrick Rucker and Ben Klayman
WASHINGTON/DETROIT (Reuters) - U.S. lawmakers on Wednesday criticized Japanese supplier Takata Corp for resisting a call by regulators to expand nationwide its regional recall of driver-side air bags that can potentially rupture upon deployment, shooting metal shards into vehicles.
The hearing by a House Energy and Commerce subcommittee comes after Takata told the National Highway Traffic Safety Administration on Tuesday that current data does not support the need for such an expanded recall.
It also said it was surprised by the agency's request because a defect investigation has not been concluded.
NHTSA late on Tuesday called Takata's response "disappointing," a sentiment also expressed by lawmakers during Wednesday's hearing.
"We are very disappointed in Takata, refusing to work with NHTSA on the deadline for a national recall of the driver-side air bags," said Republican Representative Marsha Blackburn of Tennessee.
Takata is at the center of a global safety scandal that has involved the recall of more than 16 million cars worldwide over the past six years and been linked to at five fatalities.
However, Takata and automakers have struggled to pinpoint the exact cause of the defect, and have directed a limited supply of replacement parts to regions with high humidity, which is believed to cause the air bag propellant to become more volatile.
Takata has questioned the wisdom of a U.S.-wide recall, which it says could divert replacement parts from areas where they are most needed.
Lawmakers said the supplier's answers were unsatisfactory and gave the public little confidence that it has a handle on the scope of the safety crisis.
"Complexity is not an excuse for incompetence," said Republican Representative Fred Upton of Michigan. "What should I say to the mom in Michigan who asks me if she and her family are safe behind the wheel?"
(Additional reporting by Eric Beech in Washington and Bernie Woodall in Detroit; editing by Matthew Lewis)