U.S. and Canadian citizens whose documents wouldn't measure up to new travel requirements taking effect next week are being given written instructions and a warning at U.S. ports of entry.

Beginning Jan. 31, a driver's licence will not be enough to get past U.S. Customs and Border Protection agents.

Instead, the Western Hemisphere Travel Initiative will require travellers 19 and older to produce a passport, NEXUS card or other secure ID at the Canadian or Mexican border. A driver's licence coupled with a birth certificate or other ID will be OK until next June.

The rules are outlined on "tear sheets" being handed out at the Peace Bridge in Buffalo and other ports of entry.

"This tear sheet will be given to those travellers who are not in compliance and we will be asking them to get in compliance as quickly as possible," Robert Jacksta, the border agency's deputy assistant commissioner for field operations, said at the Buffalo crossing Thursday.

"We recognize this is a major cultural change for the travelling public," Jacksta said.

Northern states worried about economic impact

Until now, residents of border cities like Buffalo and Niagara Falls routinely travelled back and forth to Canada to shop or dine by showing a driver's licence and telling an inspector where they were born and where they were going.

But "in our post 9-11 environment," Jacksta said, "oral declarations are simply not enough to ensure the security of this country."

The change applies to both Canadians and Americans, and that's not sitting well with congressional critics representing Northern border states, who fear disruptions in all-important trade and tourism partnerships.

"These ill-conceived and unnecessarily cumbersome travel requirements will have a deleterious effect on our nation's weakening economy and will adversely affect the economies of the border communities," U.S. Representative Louise Slaughter and 33 colleagues said Thursday in a letter to Homeland Security Secretary Michael Chertoff.

The group asked Chertoff to hold off on any changes until the WHTI, adopted in 2004 in reaction to the Sept. 11 attacks, is fully implemented in June 2009.

In June, Chertoff delayed the law's passport requirement for land and sea crossings until next summer. Congress then pushed it back to 2009.

"Your imminent actions not only violate the intent of the United States Congress, but threaten our nation's economic security by implementing a new, resource intensive system without ensuring a smooth transition," the group wrote.

The letter cited a Government Accountability Office report that found CBP was severely understaffed and would be unable to handle the influx of documents without significantly increasing wait times at crossings.

Some exceptions will be made at beginning

Chertoff said last week that longer lines at the border in the early days of the new policy are inevitable.

On Thursday, Jacksta said agents will make some exceptions in the beginning to avoid sending everyone without the right paperwork for a potentially lengthy secondary inspection. Those travellers will be given the tear sheet and instructed on the new rules.

"A U.S. citizen will never be refused entry into the United States," Jacksta said.

Slaughter's concerns were echoed by the Binational Tourism Alliance, whose executive director, Arlene White, predicted "more delays at the border, more confusion and frustration by the travelling public and more job losses in the area.

"The hardening of the borders since 2001 has resulted in lower North American competitiveness and productivity," added White, whose agency has offices on both sides of the border.

Jacksta said whittling down the kinds of identification accepted at the border is necessary because agents now may see more than 8,000 forms, including student library cards and baptismal certificates.

He pointed to a case in Buffalo last week involving a man from the Netherlands who was arrested after showing a Texas driver's licence and telling an agent he was a U.S. citizen.

More than 800,000 people enter the U.S. through land and sea ports each day. Between October and December, agents caught more than 1,500 making false oral declarations.