"Nothing is more important to Toyota than the safety and reliability of our vehicles, and right now we are completely focused on fixing the vehicles that have been affected under this recall," Bob Carter, Toyota group vice president said at the Chicago Auto Show on Wednesday.
He said some dealers have been open around the clock while others are carrying out the repairs at offsite facilities.
Carter added that the voluntary recall of the 2010 Prius and Lexus HS 250h models to update braking software, in response to complaints about braking problems, also is proceeding.
CBS News correspondent Dean Reynolds says some critics maintain Toyota has a history of foot-dragging when it comes to addressing concerns.
"Now it's coming home to roost, because there is just too much consumer complaint and the DOT is finally beginning to dig in," Joan Claybrook, a former NHTSA administrator, told CBS News.
Reynolds reports that Toyota's new car sales and used car values are plummeting. The price of the Prius is said to have lost $1,500 during the week the brake problems were reported.