POINT EDWARD, Ont. - Canadians are well-prepared for a new rule in June requiring passports at land crossings into the United States, but Americans may not be quite so ready, Prime Minister Stephen Harper said Friday.

Speaking within sight of the Blue Water Bridge, Canada's second-busiest commercial crossing with the U.S., Harper also said he did not expect the Americans to push the requirement date back any further, as they have done several times.

"We believe that in Canada, we are pretty much ready for that deadline," Harper said.

"We now have close to 75 per cent of adult Canadians holding passports. It's a huge number. It's been a big change over the past few years."

Washington has been implementing the passport requirement for all travellers entering the U.S. over the past several years. The move was designed to enhance the country's border security in light of the 9-11 terrorist attacks.

However, Americans have not been as quick to embrace passport acquisitions, and the number of holders has lagged relative to Canada.

American citizens are also required to hold passports when returning to their country.

"We're not as sure the Americans are ready for the imposition of their own deadline," Harper said.

"That's obviously something they will have to wrestle with in due course."

The prime minister, as part of several campaign-style swings in Ontario, was in this border community to announce $13.5 million in funding to speed up upgrades to the Blue Water Bridge to Michigan, which Harper called a crucial trade link.

Among other things, the money is to be used for adding access lanes and inspection booths. It will also allow construction, set to begin in May, to be completed two years ahead of schedule.

"Blue Water Bridge is a crucial link in trade between Canada and the United States," Harper said.

"This project will reduce border congestion, improve trade and create local jobs."

The prime minister also said no decisions had been made on proposed "border envoys" who would report to their respective governments about problems at the crossings.

He and U.S. President Barack Obama discussed ways to improve security without hampering trade at their recent meeting in Ottawa, and more talks are planned between the two governments on the issue, Harper said.