The U.S. Postal Service and Department of State are teaming up to get Americans prepared for tougher travel regulations.

Under the Western Hemisphere Travel Initiative passed in 2004, anyone entering the country after June 1 of this year will need a passport. That includes entry from some destinations where a passport was previously not necessary, such as Mexico, Canada or the Caribbean.

To make sure every one is ready for the changes, post offices throughout Missouri and the U.S. will be open Saturday for "Passport Day."

Spokeswoman Valerie Hughes says a big turnout’s expected since the June 1 deadline is just around the corner.

Kids under 16 — who will also be required to have a passport to enter the U.S. — only need to bring a birth certificate. Hughes explains what else is needed for those over 16:

* Proof of U.S. citizenship: A certified birth certificate, naturalization papers or expired passport.

* Passport books cost $100 for adults, $85 for children; passport cards are $45 for adults and $35 for children. Adult passports are good for 10 years, five years for children.

* Identification such as a valid driver’s license or military I.D.

Hughes recommends printing the application from travel.state.gov and bringing it to the passport fair already filled out, which will make the process go quicker. She says to call your local post office to see which local offices are participating and the hours of operation.

According to the State Department, the Western Hemisphere Travel Initiative is a result of the Intelligence Reform and Terrorism Prevention Act of 2004, requiring all travelers to present a passport or other document that denotes identity and citizenship when entering the U.S.

The goal of the initiative is to strengthen U.S. border security while facilitating entry for U.S. citizens and legitimate foreign visitors by providing standardized documentation that enables the Department of Homeland Security  to quickly and reliably identify a traveler.

Jessica Machetta reports [Download/listen MP3]

Missourinet