The U.S. aviation safety regulator has proposed requiring operators of some Boeing Co 787 Dreamliners to replace parts near the plane's lithium battery in an effort to improve the plane's ability to fight an on-board fire.

In a directive issued on Tuesday, the Federal Aviation Administration said it had received reports that some 787-8 planes did not have foam-like plugs properly installed as required to keep a fire-suppression chemical in an electrical compartment in the plane.

In the event of a fire, the FAA said, the condition could cause loss of the suppression chemical, known as Halon, in cargo areas, "and result in the inability to extinguish a fire and consequent loss of control of the airplane."

The compartment, known as the forward electrical equipment bay, is where one of the 787's two lithium batteries is located. The plugs go into "stringers," structural elements that run along the length of the fuselage.

The fix doesn't affect the plane's battery system, Boeing said. Boeing's 787 was grounded for three months last year after lithium batteries overheated, prompting Boeing to redesign the battery, charger and containment system.

The FAA rule applies to three U.S. planes but is likely to influence foreign operators.

Boeing said it had already advised operators to update the plugs "to ensure they are secured in the desired design configuration."

Boeing recommended in May that operators fix the problem within two years. On Thursday, theChicago-based company said it agreed with the FAA's proposal to require operators make the fix within a year.

The problem affects 88 planes of the 183 delivered through August, Boeing said.

"An engineering review determined that this improper configuration does not present an immediate safety concern for several reasons, including redundancies designed into the system and the extremely low likelihood of system activation," Boeing said in a statement.

"Regardless, it is important to return airplanes to their proper configuration," it added.

"We support the FAA's proposed rule, which would make mandatory the recommendations we provided to our operators four months ago," Boeing said.