WASHINGTON (AP) — Residents of at least 17 states are suddenly stuck in the middle of a fight between the Bush administration and state governments over post-Sept. 11 security rules for driver’s licenses — a dispute that, by May, could leave millions of people unable to use their licenses to board planes or enter federal buildings.

Homeland Security Secretary Michael Chertoff, who was unveiling final details of the REAL ID Act’s rules on Friday, said that if states want their licenses to remain valid for air travel after May 2008, those states must seek a waiver indicating they want more time to comply with the legislation.

Chertoff, as he revealed final details of the REAL ID Act, said that in instances where a particular state doesn’t seek a waiver, its residents will have to use a passport or a newly created federal passport card if they want to avoid a vigorous secondary screening at airport security.

“The last thing I want to do is punish citizens of a state who would love to have a REAL ID license but can’t get one,” Chertoff said. “But in the end, the rule is the rule as passed by Congress.”

Chertoff spoke as he discussed the details of the administration’s plan to improve security for driver’s licenses in all 50 states — an effort delayed due to opposition from states worried about the cost and civil libertarians upset about what they believe are invasions of privacy.

Under the rules announced Friday, Americans born after Dec. 1, 1964, will have to get more secure driver’s licenses in the next six years.

So far, 17 states have passed legislation or resolutions objecting to the REAL ID Act’s provisions, many due to concerns it will cost them too much to comply. The 17, according to the ACLU, are: Arizona, Colorado, Georgia, Hawaii, Idaho, Illinois, Maine, Missouri, Montana, Nebraska, Nevada, New Hampshire, North Dakota, Oklahoma, South Carolina, Tennessee and Washington state.