WASHINGTON - Federal safety regulators and Ford Motor Co. are still in talks over whether the automaker's limited recall of 135,000 F-150s over air bag issues will satisfy the government's concerns about safety.

The Dearborn automaker on Wednesday agreed to recall the F-150 pickups from the 2005 and 2006 model years because of concerns about airbags deploying without warning.

The National Highway Traffic Safety Administration asked Ford in a Jan. 26 letter to recall 1.3 million F-150s — from the 2004 to 2006 model years — after reports of 269 air bags deploying without warning and causing 98 injuries.

"The bottom line is that this problem will only multiply. To remedy it, NHTSA firmly believes Ford must initiate a recall," said the Jan. 26 letter, which was made public Wednesday, reported The Detroit News.

The letter warned that if Ford didn't agree to a recall, the agency could convene a formal public hearing to compel a recall — a rarely used step that hasn't happened in decades.

Ford resisted any kind of recall for months and defended its limited recall.

The recall is limited to trucks produced during one shift at Ford's Norfolk, Va., plant from November 2004 to June 2005 and covers 135,000 U.S. vehicles. Ford said the failure rate for the recalled vehicles was "five times the rate for trucks built at the Kansas City Assembly Plant and 29 times the rate for trucks built at the Dearborn Truck Plant."

Ford said it doesn't know why the failure rate was higher.

Ford also said owners need to take responsibility if the air bag light illuminates. "Essentially (NHTSA) is requesting that Ford conduct a recall of 1.3 million vehicles to affect the behavior of an extremely small group of owners who have shown that they habitually ignored multiple safety warnings," the company said.