The two leaders had a private bilateral meeting Sunday on the sidelines of the Asia-Pacific Economic Co-operation summit while sitting at a table under an umbrella outside their Honolulu hotel.
Obama and Harper appeared collegial as both were seen laughing during their discussion. They continued their conversation as they walked along a path with their jackets slung over their shoulders.
The White House later issued a statement, saying during the course of the APEC meetings, Obama and Harper found time to continue their regular dialogue about the two countries' relationship.
"The leaders discussed the recent announcement regarding the Presidential Permit process for the Keystone XL pipeline application," the statement said. "The president underscored his support for the State Department's announcement regarding the need to seek additional information about the Keystone XL pipeline proposal to ensure that all questions are properly addressed and all the potential impacts are properly understood."
The Canadian Broadcasting Corp. said prior to meeting with Obama Harper had reiterated his disappointment that construction of the $7 billion TransCanada Corp. pipeline from Alberta to Texas is being delayed over environmental impact concerns.
"Nonetheless, I remain optimistic that the project will eventually go ahead because it makes eminent sense," Harper told reporters.
The White House statement also said Obama "underscored the importance" of the two nations working together "to enhance economic competitiveness, create sustainable economic growth and jobs."
"He noted the important progress being made on the Beyond the Border and Regulatory Cooperation initiatives," the statement said.
"The president also welcomed Prime Minister Harper's expression of Canada's interest in seeking to join the Trans-Pacific Partnership talks and initiating consultations toward that goal. The leaders discussed the importance of meeting the TPP's high standard for trade liberalization and addressing outstanding trade and investment issues in that process."
Obama invited Harper to Washington in early December, the statement said.
Obama and Harper met alone after a North American summit was postponed because Mexican President Felipe Calderon was not in attendance because of the death of his interior minister.