President Bush, tending to relations with two border nations, sought Monday to invigorate his partnership with like-minded leaders of Canada and Mexico.

Bush arrived by mid-afternoon in the Canadian countryside, where he will promote North American integration with Canadian Prime Minister Stephen Harper and Mexican President Felipe Calderon. Police in riot gear pushed back dozens of protesters marching just outside the gate of the resort compound, where a few hundred people gathered in demonstration.

"I heard it's nothing," Harper said, dismissing the protests as Bush arrived at the posh Fairmont Le Chateau Montebello. Bush ducked a question about it and just smiled.

The two-day summit is the third of its kind during Bush's presidency, and each one has been meant to bolster a compact — dubbed the Security and Prosperity Partnership of North America — that serves as a way for the nations to team up on health, security and commerce.

The partnership of the countries is a framework for working out problems — not a deal that was ever intended to produce dramatic announcements. In turn, the White House sought to lower expectations that something bold would emerge from the meetings.

"I don't expect any major announcements," Bush spokesman Gordon Johndroe said. "I think it's a continuance of discussions that we have regularly with our two closest neighbors."

For Bush, the event also allows him to show that he does not take his neighbors for granted; they are both vital trading partners and energy providers for the U.S.

"The message for Canada and Mexico is that despite the ongoing emphasis on Iraq and terrorism in U.S. foreign policy ... the U.S. is investing time and attention on relationships with our own region," said Chris Sands, a scholar of North American studies and senior associate at the Center for Strategic and International Studies.

Bush arrived to the greeting of a Canadian honor guard decked in red coats and fur hats. Nearby, on the airport tarmac in Ottawa, a U.S. Marine collapsed and was treated by White House medical personnel and local paramedics. He was taken to a local hospital.

Meanwhile, Calderon was considering cutting his trip short to return to Mexico, where Hurricane Dean was poised to slam into the coastline. Calderon will make a decision about his plans once the hurricane draws closer to Mexico, his press office said. As of midday Monday, though, no change in schedule was anticipated.

Personally, Bush shares plenty of views with Harper and Calderon, two fellow conservatives and free-market advocates who have come into power during his second term.

It's not all cheery. Critics are angry about Canada's troop presence in Afghanistan and about the partnership among the three countries. Some Canadians see it as an insidious threat to their sovereignty, led by the United States.

The summit site is about 50 miles to the east of Ottawa, the Canadian capital.

The broad theme of the event is economic prosperity, built around several topics: border security, competitiveness with India and China, product safety and energy solutions.

Bush will also be faced with matters of specific concern to each of the countries.

He began with Harper.

Bush is sure to thank Harper for Canada's commitment to keeping troops in Afghanistan.

Meanwhile, Harper is frustrated over a U.S. law that tightened passport rules for Canadians visiting the U.S., although Bush has pledged to enforce it and has little leeway.

Harper is also expected to assert his nation's claim to the fabled Northwest Passage through the resource-rich Arctic. Competition to control the Arctic has intensified with global warming; Russia sent two small submarines to plant a tiny national flag under the North Pole this month. The U.S. and Norway also have claims.

"We look at the Northwest Passage as an international waterway, and want the international transit rights to be respected there," Johndroe said. "But certainly President Bush will listen to what Prime Minister Harper has to say."

Bush and Calderon will have their own one-on-one session later Monday.

With them, the messy issue of immigration looms large. The last time these two leaders met, in March in Mexico, Bush was optimistic about getting a new immigration law.

Since then, his plan died in Congress.

So Bush recently issued an executive order meant to tighten border security, streamline guest-worker programs and pressure employers to fire illegal immigrant workers.

The three leaders will join at day's end for dinner, then resume talks Tuesday.