Border guards began requesting passports as Canadians crossed into the United States on Monday as the Western Hemisphere Travel Initiative officially took effect just after midnight.

"For a traveller what that means is we can no longer can take an oral declaration. We can no longer take a driver's licence for identification," said U.S. chief customs and border protection officer Tom Schreiber.

People without proper documentation should be prepared to face delays, officials said. But border officials told CBC News that they would be "pragmatic and flexible" as the new rules are rolled in.

No Canadian or U.S. citizen will be denied entry at first.

"We will not refuse entry into the United States to citizens, a legal permanent resident or a bona fide Canadian visitor," Schreiber said.

Non-compliance notices issued

Anyone who doesn't have a passport will still be allowed to cross the border for the next few weeks, as long as they have such things as a birth certificate and picture identification.

But those without a passport will be given a paper that says: "Non-compliant. You are not in compliance with the secure document requirements that went into effect June 1, 2009, for entry into the United States."

"U.S. and Canadian citizens must present a secure travel document for entry into the United States at land and sea ports of entry."

U.S. border officials at Calais, Maine, reported no problems early Monday morning as people crossed into the state from St. Stephen, N.B. There were also no reports of border delays in Emerson, Man., which is a popular crossing for truckers.

The Western Hemisphere Travel Initiative, an anti-terrorism policy passed by Congress in 2004, requires travellers 16 and older who are entering the United States from Canada by land or sea to carry one of the following:

• Passport.
• NEXUS card.
• Free and Secure Trade (FAST) card.
• Enhanced driver's licence (EDL) or an enhanced identification card (EIC) from a province where a U.S.-approved EDL/EIC program has been implemented.
• Secure Certificate of Indian Status (when this certificate is available and approved by the United States).

Canadian citizens 18 years of age or under who are travelling with a school or other organized group, under adult supervision with parental/guardian consent, may present proof of Canadian citizenship alone.

Ministry of Indian and Northern Affairs is also working with the Canada Border Services Agency to create a new certificate of Indian status, which will replace the laminated cards that are currently issued, said Ray Hatfield, director general of Indian Affairs. The old cards will be accepted until the certificates become available in the fall.

Mexico and Caribbean countries are also affected by the legislation.

There are no changes to border identification rules when entering Canada. Travellers with a valid driver's licence and proof of citizenship can still enter Canada from the United States without a passport.

Tourism, retail concerns

U.S. border officials said that internal monitoring leading into the new rules indicate that about 80 per cent of U.S. and Canadian citizens already have been showing the appropriate documentation.

It's estimated 41 per cent of Canadians have a passport, but only about 20 per cent of Americans have one.

Tourism and business groups have been bracing for this day, worried many people will avoid the red tape and decide not to travel across the Canada-U.S. border.

New Brunswick Tourism Minister Stuart Jamieson told The Canadian Press the number of American visitors to the province has been dropping since the passport requirement was announced and he expects the decline to continue.

But Peter Raju, owner of Peace Arch Duty Free at the Douglas crossing between B.C. and Washington, said he is hopeful the strong dollar will help keep Canadians crossing into the border.

"We feel there will be more Canadians crossing the border taking advantage both of having a passport and the savings," Raju said.

With files from The Canadian Press