SAN ANTONIO — More needs to be done to educate border crossers on new documentation requirements to prevent lengthy delays at the ports of entry when changes take effect next year, the Canadian ambassador to the U.S. said.

"We have to do this in a way that is collaborative and cooperative," said Ambassador Michael Wilson on Nov. 28, a day after visiting the U.S. southern border at Laredo. "We think a really strong effort has to be made to manage this."

Wilson, who last visited San Antonio in 1992 to sign NAFTA on Canada's behalf, said he's concerned that confusion among border crossers and the additional time it will take for U.S. agents to check paperwork could cause frustrating backups at the ports — something that could deter tourism and stymie trade between the countries.

Starting Jan. 31, U.S. and Canadian citizens will be required to show a government-issued identity card and proof of citizenship, like a passport or birth certificate, when entering the United States by land at the northern and southern borders.

Additional passport requirements, similar to those implemented for air travelers early this year, will go into effect next summer for border crossers.

Currently, an American border crosser simply needs to verbally declare that he or she is a U.S. citizen to be readmitted from Mexico or Canada at land ports.

Nearly 296 million people entered the U.S. by land during the last federal fiscal year; three-quarters of them arrived from Mexico.

Amy Kudwa, a spokeswoman for the Department of Homeland Security, said the agency has been holding news conferences, publishing documents and trying to send a clear message to travelers about what will be required.

The new requirements will make the U.S. borders more secure, she said. But they will also make them more efficient by limiting the types of documents that U.S. agents have to verify for admission into the United States.

Wilson, a former banking executive, said his country and the United States have faced new challenges for security changes since the Sept. 11th attacks even as NAFTA has tripled trade across the continent.

The effort to balance new security concerns with the need to allow trade and economic growth has been mixed, he said.

"We know we've got to do things on the security side, but if we try to hermetically seal a country or a continent from the rest of the world, it's going to impose a significant economic cost," Wilson said. "Sometimes we get it right; sometimes we get it wrong."

For more information on new travel requirements, visit www.dhs.gov/xtrvlsec/crossingborders/whtibasics.shtm.