Honda plans to replace the replace driver's air bag inflators on 2.6 million more vehicles as it expands repairs to the entire U.S.

The Japanese automaker is the only company to comply with demand from the U.S. National Highway Traffic Safety Administration to do repairs nationwide. Honda says it's doing so to address customer concerns.

Air bags made by Japanese supplier Takata Corp. can inflate with too much force, blowing apart a metal canister and spewing shrapnel. At least five people have died due to the problem.

Honda and other automakers have limited recalls to high-humidity states mainly along the Gulf Coast. Investigators have said that the air bag inflator propellant, ammonium nitrate, can burn faster than designed if exposed to prolonged high humidity. That can cause it to inflate air bags too fast.

Last week, a top Honda executive told a U.S. House subcommittee during a hearing that his company would expand the driver's side repairs nationwide. Honda isn't calling it a recall, though, and is maintaining that the driver's air bag inflators are not defective. Instead, Honda calls the expansion a "safety improvement campaign."

Takata and Chrysler have refused the government's demand to expand the driver's side repairs nationwide. Ford, Mazda and BMW haven't decided on whether to expand repairs nationwide.

Honda's expansion brings its total driver's side repairs to 5.4 million vehicles, including Honda's most popular models. Owners in high-humidity areas began getting notices by mail in September. Those in other parts of the country will get letters over time.

Affected vehicles include the 2001 to 2007 four-cylinder Honda Accord, 2001 and 2002 V6 Accord, 2001 to 2005 Honda Civic, 2002 to 2006 Honda CR-V, 2003 to 2011 Honda Element, 2002 to 2004 Honda Odyssey, 2003 to 2007 Honda Pilot, 2006 Honda Ridgeline, 2003 to 2006 Acura MDX, 2002 and 2003 Acura TL, and the 2002 Acura CL.

Meanwhile, for passenger-side air bag inflators, NHTSA says a recall remains limited to high-humidity areas because there's no data to suggest a problem with them nationwide.