The leaders of the United States, Canada and Mexico will pledge today to source half their overall electricity with clean power by 2025, according to administration officials.

The commitment - which will be a joint one, rather than an individual commitment by each nation - represents an aggressive target given the current reliance by the United States and Mexico on fossil fuels for much of their electricity supply. Roughly 59 percent of Canada's electricity is generated by hydropower operations, with another 16 percent coming from nuclear plants, so it has already surpassed the targeted benchmark.

The new commitment includes not just renewables but also nuclear and carbon capture and storage plants and energy efficiency. Under that definition, 37 percent of North America's electricity in 2015 came from clean energy sources.

President Obama will travel to Ottawa today to meet with Canadian Prime Minister Justin Trudeau and Mexican President Enrique Peña Nieto as part of this year's North American Leaders Summit. The upcoming pledge highlights how collaboration on climate between the United States and Canada has accelerated since Trudeau, leader of his country's Liberal Party, was elected last fall.

White House senior adviser Brian Deese described it as "an aggressive goal," but one that "is achievable continent-wide."

He added that the alignment between Canada, Mexico in the U.S. on climate and energy policy "is stronger than it has been in decades... In all three countries, there is a significant move toward a clean energy economy."

Roughly 13 percent of U.S. electricity comes from hydropower and other renewable sources, according to the Energy Information Administration, with another 20 percent stemming from nuclear power plants.

Just 22 percent of Mexico's electricity generation in 2014 came from non-fossil fuels, according to its government, though leaders there have pledged to raise that figure to 34 percent by 2024.

Mexico will also pledge to reduce its emissions of methane, a powerful greenhouse gas, by 40 to 45 percent by 2025. The U.S. and Canada have already set that goal for their own methane output.

A new report by environmental experts from the United States, Canada and Mexico last week urged the three countries to work more closely on their climate goals in the wake of the international accord finalized last December in Paris.

"For the first time in recent memory, the national governments of the United States, Mexico, and Canada are politically aligned on climate change," the group wrote. "The three countries should take this opportunity to explore and launch coordinated climate initiatives that could propel the shift to clean energy across the continent and - through international leadership - accelerate the reduction of greenhouse gas pollution globally."