Takata's Hiroshi Shimizu said the company does not feel it's appropriate to expand the recall of its airbags.

The National Highway Traffic Safety Administration continues to try to reassert itself as the nation’s safety watchdog by announcing its working on building a case it can use in court against Takata Corp. and three automaker to compel them to expand the existing regional airbag recall to a national action.

David Freidman, NHTSA’s deputy administrator, said today the agency is pressuring the Japanese supplier as well as Ford, Chrysler and BMW to enlarge the recall, which would add another 5 million vehicles to action. Currently, there are just under 8 million.

Regulators will take the companies to court, if necessary, to compel them to take those steps, Friedman told reporters, adding the agency is reviewing tens of thousands of pages to develop “an airtight case” to present in federal court if the makers don’t comply voluntarily.

Friedman noted the agency is likely going to send demand notices to the three automakers telling them to recall the vehicles. Honda and Mazda have already expanded their callbacks beyond regional campaigns in high-humidity states at NHTSA’s urging.

The driver’s side airbags in question may explode when detonated sending plastic and metal fragments into the cabin of the vehicle. The problem has been tied to at least five deaths in the U.S. and dozens of injuries. Nearly 20 million vehicles worldwide have been recalled due to the problem.

(Chrysler expands Takata recall as 10 makers begin airbag probe. For more, Click Here.)

The issue is such a problem that 10 automakers – Toyota, Honda, Ford, Chrysler, BMW, GM, Mitsubishi, Subaru, Nissan and Mazda – met at a hotel just outside of Detroit last week and agreed to hire and share the costs for an outside company to conduct tests on the airbags to determine what’s causing them to explode.

(Click Here for details about the alphabet soup that is Chrysler’s new name.)

Takata is resolute in its opinion that a national recall is unnecessary and even dangerous because it would divert replacement parts away from the regions of the company most impacted by the problem.

(To see how Volvo plans to sell cars to the public via the Internet, Click Here.)

Friedman has remained equally resolute that regulators will force Takata and the other companies to take the recall a national status.