Toyota Motor Corp will soon offer to fix the accelerator pedals of up to 4 million vehicles in the United States that are subject to the company's largest ever safety recall, Kyodo News reported on Saturday.

Toyota is believed to have agreed with U.S. authorities to voluntarily repair the accelerator pedals, Kyodo said, citing sources familiar with the matter. It was unclear what the fix would involve.

Toyota spokesman Hideaki Honma denied that the company had reached an agreement with the U.S. National Highway Traffic Safety Administration (NHTSA) on the matter, and said the talks were proceeding.

NHTSA in Washington said on Saturday that discussions with Toyota continue "as to what the remedy will entail" and that the accelerator pedal is "among the subjects under consideration."

Toyota, the world's top automaker, said in late September it would recall some 3.8 million vehicles in the United States because of the risk that a loose floormat could force down the accelerator, a problem suspected of causing crashes that killed five people.

Toyota has said it was confident the problem is linked to floormats and not a vehicle design flaw or problems with components related to braking, fuel or accelerator systems.

NHTSA has said it discussed "several vehicle-based" factors that may contribute to pedal interference and a driver's ability to control and stop the car when the accelerator gets stuck.

Kyodo said the company had opted to offer to fix the accelerator pedal, but has no plans for a recall beyond floormats.

Toyota has said the cost of any related repair work will have no effect on its business as the company has set aside nearly $5.6 billion in provisions for recalls.

The investigation has included the Camry and Avalon sedans, the Prius hybrid, the Tacoma and Tundra pickup trucks and luxury Lexus models, the IS250, the IS350 and the ES350.