The United States, Mexico and Canada are set to announce that 50 per cent of North America's electricity will come from clean power sources by 2025 at the Three Amigos summit in Ottawa this week.

The U.S. State Department and the Prime Minister's Office said the agreement will underscore the emphasis the three North American leaders will place on using the already integrated economic relationship to harmonize environmental policies.

Currently 37 per cent of all of North America's power comes from non emitting sources according to the State Department.

The 2025 targets are ambitious for the U.S. and Mexico. Currently only about 13 per cent of U.S. electricity comes from hydroelectricity or renewable energy sources like wind and solar, with another 19 per cent from nuclear. About 25 per cent of Mexico's electricity is from non-fossil fuel producing sources, including nuclear.

The commitment is a big trade opportunity for Canada, which has a lot more clean power to spare, as 60 per cent of the country's electricity comes from hydro and another 3 per cent from solar and wind. The amount of non-emitting power climbs to 81 per cent if nuclear-generated power is included. There will be a renewed emphasis on integrating the electricity grid between the three countries to allow this clean power to be moved easily across borders.

The PMO and State Department confirmed Mexico will also sign on to the same targets as the U.S. and Canada — reached during Prime Minister Justin Trudeau's visit to Washington in March — to reduce methane and short lived climate pollutants like black carbon and hydrofluorocarbon (HFC), a material used primarily in refrigeration.

The target commits all three countries to cut those emissions by 40 to 45 per cent by 2025, although negotiations continued over the weekend to hammer out the final details of the announcement.

North America produces about 20 per cent of the world's methane emissions, which mostly leak out of oil and gas installations and pipelines. Methane is considered 25 times more potent than CO2 because it traps heat more readily.

Movement by the U.S. and Mexico on the clean energy front is a sign that "progress is possible," a source with knowledge of the discussions told CBC News on background, adding further energy integration will be crucial to meeting ambitious targets for GHG emission cuts.

"The environment and energy will definitely be the major topic of the summit. It's important that we make progress on collective action, it's at the top of the list," the source said.

Protecting biodiversity

The final text of the deal reached at the summit will also include a commitment to protect biodiversity in North America.

Millions of birds fly between the three countries every year, but annual numbers show many are declining because of environmental degradation.

The monarch butterfly, a species that migrates between Canada, the U.S., and Mexico, is facing threats to its habitant in all three countries, something the leaders are expected to address.

First summit in more than 2 years

Mexican President Enrique Peña Nieto is in Canada this week for a state visit.

He will spend part of the day Tuesday on Parliament Hill, where he will have a bilateral meeting with Trudeau and take part in a joint media availability at 11:30 a.m. ET. Later, Gov.-Gen. David Johnston will host the Mexican leader for a state dinner at Rideau Hall.

The pair will then attend the North American leaders summit with U.S. President Barack Obama on Wednesday. Obama will address both houses of Parliament that evening.

Last year's trilateral summit was postponed by former prime minister Stephen Harper amid the Canada-U.S. dispute over the Keystone XL oil pipeline, and an ongoing Canada-Mexico fight over visa requirements. The meeting will be the first between Canada, the U.S. and Mexico in more than 2½ years.