If Santa leaves an international travel voucher in your Christmas stocking this year, Uncle Sam hopes it won't become a lump of coal soon after you pack your bags.

The U.S. Department of Homeland Security (DHS) and the U.S. Department of State (DOS) remind vacationers that beginning Jan. 31, all adult travelers will be required to present proof of citizenship, such as a birth certificate, and proof of identity, such as a driver's license, when entering the United States through land and sea ports of entry.

Officials say the change is necessary in order to prepare travelers and ease the transition to the future requirements of the Western Hemisphere Travel Initiative (WHTI).

WHTI establishes documentation requirements for travelers entering the United States who were previously exempt, including citizens of the U.S., Canada and Bermuda.

During a phone interview Thursday, DOS spokesman Curtis Cooper said such requirements for air travelers actually were implemented nearly a year ago. Additional changes to be made during the summer of 2008 will impact all travelers, regardless of their mode of transportation.

“All persons (traveling by air) are already required to carry a passport or other travel documents,” Cooper said. “As of Jan. 31, 2008, U.S. and Canadian citizens need WHTI-compliant document - a government-issued photo I.D. such as a driver's license and birth certificate.

As recommended by the 9/11 Commission, Congress enacted WHTI in the Intelligence Reform and Terrorism Prevention Act of 2004. According to a DHS statement, WHTI will “result in both enhanced security and increased facilitation across the border once implemented. During this transition, DHS and the Department of State are working diligently to minimize the impact on legitimate trade and travel.”

Right now, U.S. Customs and Border Protection (CBP) officers may accept spoken declarations of citizenship from U.S. and Canadian citizens planning to enter the United States through a land or sea border. But, at the end of next month:

• Oral declarations of citizenship alone will no longer be accepted.

• U.S. and Canadian citizens ages 19 and older will need to present a government-issued photo ID, such as a driver's license, along with proof of citizenship, such as a birth certificate or naturalization certificate.

• Children ages 18 and under will only be required to present proof of citizenship, such as a birth certificate.

• Passports and trusted traveler program cards - NEXUS, SENTRI and FAST - will continue to be accepted for cross-border travel.

All existing nonimmigrant visa and passport requirements will remain in effect unchanged.

Cooper said those who work in the countries bordering the continental U.S. need to pay close attention to the new rules, as does anyone who regularly makes the trek on vacation.

“Typical American travel plans may include travel across the Canadian or Mexican border,” he said. “It's important to know what's required, especially before summer travel.”

DOS officials note the current turnaround time for a passport is four to six weeks, so it's best not to wait until the last minute to fill out an application.

Cooper said, “The best advice I can give is go ahead and get that passport now.”

Susan Druhan, an agent with Springdale Travel in Fairhope, said her clients are kept up to date on all changes made regarding travel requirements.

“It's in every e-mail and all our signatures,” she said. “When people inquire about trips, one of our qualifying questions is about passports. Our clients are very well informed.”

Druhan said her Gulf Coast clients who requested passports early this summer usually waited several months to receive one, while six to eight weeks is the typical delay now. She added, “We ask everyone to give themselves 12 weeks. A great deal of people have already obtained their passport.”

But she advises everyone to get all the facts about existing and future DHS and DOS requirements by sitting down with a local travel agent, who receives updates and training so they'll know what is needed.

“That's the benefit of booking through a travel agency instead of online,” Druhan said.

For information about obtaining a U.S. Passport, visit www.travel.state.gov or call toll free, (877) 487-2778.

Specific documentation requirements for land, sea and air travel may be found at www.cbp.gov/xp/cgov/travel/vacation/ready_set_go/.

To learn more about NEXUS, SENTRI and FAST, visit www.cbp.gov/xp/cgov/travel/trusted_traveler/.