Five Canadian provinces and six Northeast US states have agreed to fight US legislation that would require passports or sophisticated ID cards to enter the US from Canada.
The new rules to take effect from 2008 - aimed at tightening security after the September 11 attacks - would create a bureaucratic nightmare, damage trade and shake up border life, said the US states and Canadian provinces.
"The impact would just be devastating," Quebec Premier Jean Charest told the annual Conference of New England Governors and Eastern Canadian Premiers.
"This needs further thought before it's implemented. We need to bring a real sense of urgency to this," he said.
Under rules written by the US State and Homeland Security departments designed to implement legislation passed by Congress in 2004, passports or credit card-sized PASS cards with biometric features will be required for anyone crossing into the United States from Canada by land starting on January 1, 2008.
Senior officials from the five Canadian provinces and US border states said the rules could drive a wedge between border communities that are culturally and economically entwined, and strain the world's biggest trading relationship by slowing the $1.1 billion in trade flowing each day across the border.
More than 300,000 people travel between the United States and Canada each day. Only about 20 per cent of US citizens and 40 percent of Canadians hold passports, which cost nearly $100. The PASS cards would cost about half that price.