2.7 million Jeep vehicles are being recalled, with fears that fires could break-out if they are rear-ended.
The recall includes 1993 to 2004 Jeep Grand Cherokees, and 2002 to 2007 Jeep Liberty's.
The NHTSA warns that a crash from behind could puncture the fuel tank, located in the rear of the vehicles, spill fuel, and potentially cause a fire. The government watchdog says the defect may have been responsible for up to 51 deaths.
Chrysler initially disagreed with the NHTSA, and refused to recall the vehicles, before changing course.
"...Chrysler Group recognizes that this matter has raised concerns for its customers and wants to take further steps, in coordination with NHTSA, to provide additional measures to supplement the safety of its vehicles," a company statement said.