TOKYO--Takata Corp. (7312.TO), the maker of air bags subject to multiple recalls, said it is concerned its efforts to replace air bags in high priority regions could be diverted if it needs to expand regional recalls in the U.S. to include the rest of the country.

U.S. auto safety regulators called Tuesday for recalls of millions of additional driver air bags by Takata and several big auto makers. Ten auto makers have recalled 7.8 million vehicles in the U.S. in the last two years over Takata-made air bags that could explode and shoot out shrapnel at people inside the car, an issue linked with five deaths.

Some auto makers are limiting their recalls to certain hot and moist U.S. regions including Florida and Puerto Rico. Auto makers, Takata and the National Highway Traffic Safety Administration are probing why certain Takata-made inflaters have been rupturing and whether exposure to high humidity and temperature has any impact.

"Takata is concerned that a national recall under these circumstances could potentially divert replacement air bags from where they're needed, putting lives at risk," Alby Berman, a U.S.-based Takata spokesman, said in a statement. "Takata is prepared to move forward with an appropriate expansion of the recalls should the scientific analysis and evaluation as conducted by Takata and NHTSA indicate a risk to safety beyond the current scope of the field actions."

Write to Yoko Kubota at yoko.kubota@wsj.com

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