The Ford Motor Company has announced a huge recall of 13 million Firestone Wilderness AT tyres on its vehicles at a cost of $2.1 billion.
It is the latest move in a controversy involving the tyre-maker over who is to blame for accidents killing at least 174 people.
Ford said it had lost confidence in the ability of Firestone tyres to keep Ford customers safe.
Ford chairman Mr William Clay Ford Jr. made the announcement a day after Firestone severed its nearly 100-year-old relationship with Ford.
Firestone said its tyres were safe and said Ford was ignoring safety problems with its Explorer sport utility vehicle.
The company said it was taking urgent action to replace the Firestone tyres - which it had called "world class" last year - because new data showed a risk of tread separation and other problems for Wilderness AT tyres higher than similar tyres on other sports utility vehicles - especially as the Wilderness tyres age.
Firestone recalled 6.5 million ATX and Wilderness AT tyres last August, and those tyres have been linked to traffic deaths in the United States. Ford and Firestone issued 1.5 million new Wilderness AT tyres in the previous recall.
"Some of these tyres were sending us early warning signals about future problems," Ford Chief Executive Mr Jacques Nasser said in the news conference."On behalf of our customers, we will not ignore these early warning signals. Based on the information we now have, we feel it is our responsibility to act immediately."