New U.S. rules on cross-border travel that take effect Monday represent a "heightened militarization" that will hurt the traditionally close relationship between border communities, the mayor of Sarnia, Ont., said Sunday.

"That longest and friendliest border in the world is now an invisible Berlin Wall," Mike Bradley told CBC News, responding to the new requirement that travellers carry a secure document to enter the U.S. by land. It is the latest in a series of security measures implemented since the terror attacks on New York and Washington D.C. on Sept. 11, 2001.

The border city mayor predicted a "dramatic" decrease in traffic flowing between the two countries — that Americans won't spend the money on documents now needed for a single-day trip.

Bradley said border security has already been significantly beefed up.

"[There are] helicopters by the hour, heightened security. The Americans increased spending by $2 billion last year alone just to patrol the border.

"We now have huge surveillance cameras going in across from Sarnia and all the way down the St. Clair River to Windsor, that will keep track of Canadians on the Canadian side of the border," he said.

Starting at 12:01 a.m. Monday, both Canadian and U.S. citizens will need a passport or equivalent new identification for border crossings.

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.

Border towns like Niagara Falls, Ont., are getting ready for what's normally a busy tourist season. But it seems some Americans feel the steep price of coming to Canada isn't worth it.

"We don't have a passport and it's like $100 to get one, as I understand, and so we decided to go for one last time," said a man from the U.S. who was visiting Niagara Falls, Ont., on Saturday.

Niagara Falls Tourism chairman Wayne Thomson, who promotes business on the Canadian side, worries the price of passports may be too much, especially for American day trippers.

Few Americans have passports

"The concern is over people who may not have the financial resources and don't have passports but would like to slip across the border and go to Marineland for the day with their family and go back at night," he said.

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

The Anchor Bar in Buffalo, N.Y., has always been a favourite hangout for locals and Canadians. Ivano Toscani, its host and executive chef, is hoping the Canadians will still show up after the border rules go into effect.

"Being so close to Canada, I know that we do have a lot of Canadian friends coming over here all the time, especially when we have a football game going on," he said.

Brief grace period

Americans returning home will also have to present one of the newly required documents proving their identification and citizenship. However, Chief Ron Smith of U.S. Customs and Border Protection in Detroit said his department plans to give unaware travellers a break for an unspecified period.

Smith told the Observer newspaper in Sarnia, Ont., that people who don’t have the right documents will be given a written notice explaining the new rules and sent on their way.

An official with the U.S. Border Protection agency told CBC News its border guards will be lenient with people who forget their passports at first, but "not for long."

U.S. Customs and Border Protection Acting Commissioner Jayson P. Ahern is quoted on the agency's website saying that agents "will be practical and flexible in implementing [the new rules] using the same informed compliance approach that proved successful during other major changes at our borders over the last two years."