Harper arrived in Mexico earlier this week for one-on-one talks with Mexican President Enrique Pena Nieto. "As energy- and resource-rich nations," both parties can find ways to work together to benefit from those reserves, the prime minister said in a statement Tuesday.
Harper has tried to add a layer of diversity to an energy-based economy that relies almost exclusively on the United States for oil exports.
Nevertheless, Harper said the Keystone XL oil pipeline planned through the United States from Alberta was on Wednesday's agenda.
"I will raise the issue in private [with President Barack Obama]," he was quoted by the Globe and Mail newspaper as saying.
TransCanada asked for U.S. approval of the cross-border pipeline more than five years ago. Environmental groups have protested the project because of the perceived danger from the more viscous form of tar sands crude oil found in Canada, though a January assessment from the U.S. State Department gave the project a general clean bill of health.
The Globe and Mail reported officials from Washington said Harper shouldn't expect an answer on the project.
Obama said he'd weigh the national interest of Keystone XL against its environmental footprint. Opponents said the State Department's assessment was skewed in favor of the energy industry.