Toyota has admitted it took 'too long' to deal with safety issues, which led to the recall of 8.5m vehicles worldwide.
In a statement, James Lentz, the head of Toyota in the US, said the company acknowledged and apologised for its mistakes.
Mr Lentz is to face questions from a US congressional committee this afternoon.
In recent months, Toyota has experienced problems with accelerator pedals and with the braking systems on its hybrid models.
Toyota president Akio Toyoda, who tomorrow is to appear before a different congressional panel - the House Oversight and Government Reform Committee - published an article in the Wall Street Journal in which he vowed that his beleaguered company would do much better in responding to safety issues.
'I recognise that we must do better - much better - in responding to safety issues,' Mr Toyoda wrote, vowing that he is 'personally leading a company-wide effort to institute more stringent quality control'.
'We've begun a top-to-bottom review of our quality control processes from design to production, sales and service,' he said.
'All Toyota vehicles bear my name. When cars are damaged, it is as though I am as well,' wrote the Toyota company president, grandson of the founder.
Toyota, which dethroned General Motors as the top seller in the US, is fighting to maintain its previously stellar reputation for quality, safety and reliability.
