Japanese auto parts giant Takata agreed to double a recall of US cars with potentially deadly airbags to a record of nearly 34 million vehicles, officials said, sending the firm's shares plunging in Tokyo on Wednesday.
Takata is also admitting for the first time that its airbags installed in the cars of 11 major automakers are defective, US Transportation Secretary Anthony Foxx announced, blaming the problem for "at least" five deaths.
But officials said it could take years to get enough replacement airbag inflators -- the source of the problem -- for all the cars equipped by Takata.
"The Department of Transportation is taking the proactive steps necessary to ensure that defective inflators are replaced with safe ones as quickly as possible, and that the highest risks are addressed first," Foxx said.
"We will not stop our work until every airbag is replaced."
The recall, the largest in US auto history, comes after Takata Corp and its US subsidiary TK Holdings officially agreed in a consent order with the National Highway Traffic Safety Administration (NHTSA) that a defect related to the inflators raised safety issues.
The move is aimed at replacing a defect in the airbags' inflators that can cause them to deploy with explosive force, sending metal shrapnel hurtling toward drivers and passengers.
The US announcement does not include millions of other vehicles recalled in other countries over the same problem.
A Takata spokesman was unable to give a global recall tally, and said the firm, one of the world's biggest airbag suppliers, was discussing the figure with its automaker clients.
Takata is facing calls for a criminal probe and was accused in a US class-action lawsuit of "deception and obfuscation" over the defect. Its biggest airbag client, Honda, has been named in the claim that alleges the pair conspired to hide the flaw for years.
In Tokyo, Takata shares nosedived 12% before recovering slightly to end Wednesday morning's session down 8.76%. The stock has lost more than half its value since the start of last year.
"Reacting to the bad news, investors are saying to themselves 'again?!'," said Nobuyuki Fujimoto, senior market analyst at SBI securities.
Mark Rosekind, head of the NHTSA, said automakers that installed the Takata airbags in their cars and trucks would now have to announce specific vehicle recalls.
Those automakers are Honda, Toyota, General Motors, BMW and Ford, among others.
"From the very beginning, our goal has been simple: a safe air bag in every vehicle," Rosekind told a news conference.
"The steps we're taking today represent significant progress toward that goal."
Takata issued four separate defect reports to the agency, one dealing with driver-side airbags and three with passenger-side units.
The defect could lead to "over-aggressive combustion" that could cause the body of the inflator to rupture, it said.
In that event, "metal fragments could pass through the airbag cushion material, which may result in injury or death to vehicle occupants."
The issue came to the forefront last year with congressional hearings in which Takata executives appeared evasive and uncooperative.
The NHTSA began fining the company $14,000 a day in February this year to pressure it to supply documentation on internal probes into airbag issues dating back more than a decade.
Rosekind said the accumulated penalties have topped $1 million, but the daily fine has been suspended since Takata "stepped up" to cooperate with NHTSA investigators.
The company could still face more civil and criminal fines from various government agencies, depending on results of ongoing investigations and its cooperation with investigators, according to the consent order.
A number of class-action lawsuits have been initiated since last year that could possibly lead to substantial damage payments.
Five deaths in the United States, and one elsewhere, have been linked to the airbag problem.
However, the root cause of the inflator explosions is not completely understood. Investigators know that hot, humid weather is prone to causing the problem, but that does not explain all the incidents.
And supply of replacement inflators is small, which will delay repairs.
"This is, over the long haul, going to be very involved and complex," Rosekind said. "It could be some years."