The company has said it is also considering whether it needs to announce a recall on cars sold in Europe, where the same parts are used in millions of models already sold.
The problem could lead to accelerator pedals sticking in the depressed position, causing acceleration without warning.
The recall is expected to cause major dent in Toyota's earnings, as well as the company's reputation for safety and quality.
It could also undermine its recovery from plunging automotive sales around the world caused by the financial crisis.
The automaker's shares fell 4.3 per cent in Tokyo trade Wednesday following the sales suspension announcement.
Toyota has already forecast a $3.9bn operating loss for the year to March, with a return to profit not expected until well into 2011 at the earliest.
Annual combined North American sales of the eight cars involved in the sales suspension and recall amount to more than one million units.
Bob Carter, Toyota's US vice president, said the company was taking the measures needed to ensure safety and restore confidence among Toyota customers.
"This action is necessary until a remedy is finalised," he said in a statement.
"We're making every effort to address this situation for our customers as quickly as possible."