Bill and Hillary Clinton's nonprofit received hundreds of thousands of dollars from a Canadian government agency.

Ottawa's Foreign Affairs, Trade and Development Department in 2014 donated between $250,000 and $500,000 to the Clinton Foundation in an apparent attempt to promote the embattled Keystone XL project, The Hill reports.

An unnamed spokesman for the nonprofit, however, told the Wall Street Journal that the agency office from which the Canadian donation originated is separate from the one that advocates for the pipeline. The Clinton Foundation needs to raise money for many of its projects, which include global education, health care and environment initiatives, he added.

The Canadian and other foreign contributions could become a hot issue if Hillary Clinton embarks on a 2016 White House bid. The former Secretary of State is seen as the clear Democratic front-runner and is expected by many to run, though she has yet to formally announce her campaign.

Donors aside from the Canadian government include oil and gas firms ExxonMobil, ConocoPhillips and Anadarko Petroleum, and the contributions are a concern to environmentalists who oppose the controversial Keystone pipeline, the National Journal noted. ExxonMobil alone has donated between $1 million and $5 million.

"We've long been concerned about Hillary Clinton's ties to the oil and gas industry," said Ben Schreiber, the climate and energy program director for Friends of the Earth. "It doesn't shock us to see that these companies have been giving to the foundation, but it certainly raises a red flag. We're concerned about the influence that these petrodollars have."

While the Clinton Foundation has received substantial sums from corporate donors, the Wall Street Journal also points to an uptick it contributions from foreign governments. In 2013, Australia, Italy, the Netherlands and Norway chipped in, but the number of governments that donated in 2014 appeared to have doubled from the previous year.

The oil-rich United Arab Emirates gave between $1 million and $5 million in 2014. The German government, also a first-time donor, contributed between $100,000 and $250,000.