Bracing for lengthy delays as a new security law takes effect, officials said Wednesday that officers will be added at U.S. borders with Mexico and Canada to try to ease passport-inspection problems. Beginning today, Americans returning from Mexico and Canada must show valid passports, a sharp departure from previous regulations that let U.S. citizens use only a driver license as proof of residency reports the Daily News.

And while the new regulations have been widely publicized, officials said they still expect some travelers to be caught unaware - resulting in lengthy backups while officers investigate their citizenship.

Passport issuers said the new regulations - along with a $3 increase to take effect Friday in the cost of a passport - have boosted applications.

“We’ve seen a steady increase (in applications) over the past several years,” said U.S. Postal Service spokesman Larry Dozier.

“We’ve had passport fairs at post offices all over California and across the nation because of the changes in passport regulations.”

The new restrictions have drawn criticism from Congress, especially representatives of states bordering Canada who say it will hurt tourism and commerce.

Read it here: Passports required today at U.S. borders with Mexico, Canada