Harper, U.S. President Barack Obama, and Mexican President Enrique Pena Nieto are scheduled for three-way talks covering areas of mutual interest.
At the top of the agenda for Mexico, reports say, are Canada's visa requirements for Mexican visitors. While the prime minister isn't expected to drop those barriers immediately, there may be some easing of the application process.
There are hopes that Canada and Mexico may agree sometime soon on "Nexus-style" travel permits that would allow legitimate travellers to visit participating countries with fewer restrictions.
Mexico is said to be very frustrated with Canada's refusal to drop visa restrictions for Mexicans visiting Canada.
"It's an insult to the 'new Mexico,'" Carlo Dade, director of the Canada West Foundation's Director of the Centre for Trade & Investment Policy, told CBC News.
"It's also against competitiveness. This isn't about Canada and Mexico. This is about North American competitiveness."
Harper could be in for disappointment, too, as Obama is unlikely to give him his long-awaited decision on the Keystone XL pipeline.
The formal name for the trilateral meeting is the North American Leaders’ Summit (NALS).
Previous summits were held in:- Washington, D.C. (April 2012).
- Guadalajara, Mexico (August 2009).
- New Orleans (April 2008).
- Montebello, Que. (August 2007).
- Cancun (March 2006).
- Waco, Texas (March 2005).