Canadian Prime Minister Stephen Harper will host his American and Mexican counterparts for their annual summit "later this year," his office said Thursday, denying reports he had cancelled it over friction with Washington.

The partners in the North American Free Trade Agreement typically meet in February or March for what is often referred to as the "Three Amigos Summit" to discuss trade and security matters.

Reports on Thursday suggested it had been scrubbed this year over US delays in approving the cross-border construction of the controversial Keystone XL pipeline, which Ottawa supports, to move oil from the Alberta oil sands to refineries along the US Gulf coast.

The US House of Representatives last Friday approved a Republican measure authorizing the Keystone XL pipeline project, hours after a state court removed a legal roadblock to its construction.

But US President Barack Obama vowed to veto the measure.

"While no date has been announced for the meeting, we intend to host the North American Leaders' Summit later this year," Harper's spokesman Jason MacDonald told AFP.

A senior Canadian official said the agenda is still being finalized, adding that neither a visa row with Mexico nor the pipeline issue are new irritants in the trilateral relationship.

White House spokesman Josh Earnest said: "It's my understanding that the North American summit has been postponed from early this year to later this year.

"I don't know the exact reason for the change in the date," he said, adding with a grin: "I assume the weather (in Canada) would be better later in the year than in February."

He also dismissed suggestions that the Keystone project was hurting ties with its northern neighbor and closest ally, saying: "The relationship we have with Canada is far deeper and far broader than this one construction project."

Last year in Mexico City, the three leaders agreed on issues ranging from making trade flow more easily within North America, protecting the region's Monarch butterfly and continuing cooperation on security.

Obama gave no hint to Harper then as to whether his administration would finally make up its mind on the Keystone XL pipeline project, which was first proposed in 2008.

Canadian Resources Minister Greg Rickford spent two days this week in Washington lobbying for the Keystone project, noting that there are some 70 pipelines that cross the Canada-US border already and saying: "What's one more?"

Environmentalists and other critics deride the oil sands as "tar sands" that take too much energy and water to process. Their fight against the pipeline is widely seen as a proxy for curtailing oil sands development and its impact on global warming.

Harper, meanwhile, has repeatedly pledged to nix a visa requirement for Mexican travellers, but it remains in place. The policy was originally set to stem a brief flow of illegal asylum seekers into the country.

The 20-year-old NAFTA trade bloc represents 450 million people producing US$17 trillion worth of goods and services, according to US government figures.