WASHINGTON — President Bush is tending to his country’s relationship with Canada and Mexico one last time, trumpeting trade over the “scare tactics” of economic isolation.

Mr. Bush joins Prime Minister Harper of Canada and President Calderon of Mexico today in New Orleans for his fourth and final North American Leaders’ Summit.

This year’s event has the intended twist of giving an economic and symbolic boost to the host city. Almost 32 months after Hurricane Katrina struck, New Orleans is still recovering — with uneven success — from the most brutal natural disaster in American history.

Most of Mr. Bush’s time will be spent in a hotel and a historic former city hall in the Central Business District, far from the residential areas hit hardest by Katrina. His agenda includes a few events of local flavor, but they are secondary to diplomatic talks.

Despite its lofty name, the two-day summit lacks a defining issue and is not expected to yield any major announcements. It is more like a progress report on how the three countries are integrating — important for commerce and security, but not exactly enticing.

America and its two neighbors already have the largest free-trade zone in the world, and an economic relationship that has swelled to nearly $1 trillion a year.

To bolster that cooperation, the countries have made a concerted effort to harmonize standards on everything from food safety to baggage screening to energy efficiency. Mr. Bush and his counterparts championed this effort three years ago and keep refining it.

In New Orleans, the leaders will push anew to streamline the rules for all three countries. The areas of focus this time include fuel efficiency standards; crackdowns against counterfeit or pirated goods; long-term plans for repairing roads and bridges; responses to natural disasters and other emergencies near the borders; and coordination on recalls of unsafe products.