Toyota has said it will co-operate fully with the US investigation
Embattled Japanese carmaker Toyota is considering a recall for the Corolla, the world's best-selling car.
It said no decision had been made as it was still looking into complaints over the power-steering on the Corolla - which is not sold in the UK.
Toyota also denied any cover-up as the US investigates whether it was quick enough in recalling millions of cars over problems affecting other models.
The US car safety watchdog has ordered a probe into Toyota's recalls.
Toyota said it would "co-operate to provide all the information they have requested" on the US inquiry.
The carmaker said potential complaints with the Corolla in the US currently numbered less than 100.
The Corolla has not been sold in the UK since early 2007, when the Auris model took over.
New brake system
By Roland Buerk, BBC News, Tokyo
Just when Toyota's problems were dropping out of the headlines, in Japan at least, the company's recall crisis could be about to widen.
After recalls over accelerators sticking or getting snagged in floor mats, and brakes, the issue now may be with the power steering in the Corolla, the world's best-selling car.
That executives chose to mention the Corolla when they say they are not certain there is a problem with the car says a lot about the pressure Toyota is under in the United States.
There's a Congressional hearing in Washington on the accelerator issue next week and US officials are demanding documents to establish if Toyota organized recalls in a 'timely manner' after reports of cars speeding out of control.
In a wide-ranging press conference in Tokyo, Toyota president Akio Toyoda said that the carmaker would add a brake-override system to all new Toyota vehicles as it seeks to recover from a global car recall.
The new system will cut engine power when the accelerator and brakes are applied at the same time.
And Mr Toyoda denied that the firm had tried to cover up its problems. "We have not withheld information and we shall not do so in the future," he told reporters.
He also said that he would not be attending a US Congressional hearing into the recalls set for 24 February.
Instead, Toyota's US executives will go, as Mr Toyoda focuses on the firm's quality issues.
He also said it would create a new global quality committee. The newly-announced Special Committee for Global Quality will hold its first meeting on 30 March.
On Wednesday, the carmaker took out full-page adverts in major Japanese newspapers to apologise for the recent recalls.
TOYOTA RECALLS: STORY SO FAR
September 2007, US: 55,000 Camry and Lexus cars in floormat recall
October 2009, US: 3.8m Toyota and Lexus vehicles recalled due to floormat problem
November 2009, US: floormat recall increased to 4.2m vehicles
January 2010, US: 2.3m Toyota vehicles recalled due to accelerator pedal problems (of those, 2.1m already involved in floormat recall)
January 2010, US: 1.1m Toyotas in floormat recall
February 2010, Europe: 1.8m Toyota's in pedal recall
February 2010, Japan, US: 200 reports of brake faults in new Prius. Cars recalled
February 2010, worldwide: 436,000 hybrid vehicles in brake recall. Also, 7,300 Camry vehicles recalled in the USover potential brake tube problems
February 2010, US: 8,000 Tacoma pick-up trucks recalled over concerns aboutdefective shafts
Toyota is continuing to recall 8.5 million vehicles worldwide because of problems linked to faulty accelerator pedals, accelerator pedals getting stuck in floor mats, and braking systems.
The saga began in the US with reports that accelerator pedals were getting caught under the floor mats.
The Japanese car giant began taking back vehicles potentially affected by that problem in October last year and Toyota redesigned the mats.
The floor mat issue affected a number of vehicles in the US, but not in the UK.
Later, separate acceleration problems were found to be caused by the pedal sticking.
The National Highway Traffic Safety Administration (NHTSA) said on Tuesday that it wanted to find out if Toyota conducted the recent recalls "in a timely manner".
The NHTSA said it was "requiring Toyota to provide documents showing when and how it learned of the defects affecting approximately six million vehicles in the US alone".
It said federal law required all carmakers to notify it within five days of discovering a safety recall, and to conduct a recall promptly.
Responding to the NHTSA, Toyota said it took responsibility for vehicle safety seriously and also recognised its responsibility to alert government officials of any safety issue "in a timely manner".
Toyota announced on 26 January that was suspending sales and production of eight models in the US, as it sought to resolve its problems.