Chrysler has refused to recall 2.7m Jeep Liberty (exported as Cherokee) and Grand Cherokee vehicles as requested in a letter from NHTSA (National Highway Traffic Safety Administration).

NHTSA has, since 2010, been looking into reports of fuel leaks after fuel tanks on these models ruptured in rear-end collisions.

In a 'white paper', Chrysler said: "A review of almost 30 years of field data revealed an extremely low number of rear impact crashes with fire or fuel leak that occurred in a fleet of more than five million subject vehicles that have travelled more than 500 billion miles over 50 million registered vehicle years."

But NHTSA has issued a recall request letter proposing that Chrysler recalls the 1993-2004 Grand Cherokee and 1993 to 2004 Liberty - about 2.7m vehicles).

"Chrysler Group has been working and sharing data with the Agency on this issue since September 2010. The company does not agree with NHTSA’s conclusions and does not intend to recall the vehicles cited in the investigation. The subject vehicles are safe and are not defective," the automaker responded.

"We believe NHTSA’s initial conclusions are based on an incomplete analysis of the underlying data, and we are committed to continue working with [NHTSA] to resolve this disagreement."

"The safety of drivers and passengers has long been the first priority for Chrysler brands and that commitment remains steadfast,” added chairman and CEO Sergio Marchionne.

“The company stands behind the quality of its vehicles. All of us remain committed to continue working with NHTSA to provide information confirming the safety of these vehicles.”

Chrysler said the vehicles met and exceeded all applicable requirements of the Federal Motor Vehicle Safety Standards, including FMVSS 301, pertaining to fuel-system integrity.

"Our analysis shows the incidents, which are the focus of this request, occur less than once for every million years of vehicle operation. This rate is similar to comparable vehicles produced and sold during the time in question.

"Chrysler Group stands behind the quality and safety of its vehicles. It conducts voluntary recalls when they are warranted, and in most cases, before any notice or investigation request from NHTSA. "