Natural Resources Minister Joe Oliver says with or without the approval of the Keystone XL pipeline, the Alberta oilsands will continue to be developed.

Oliver made the comments Monday during a stop in Washington, D.C., where he met with U.S. Energy Secretary Ernest Moniz.

Referencing a report released by the U.S. State Department, Oliver told reporters: “If Keystone wasn’t developed there would effectively be as much development of the oilsands in any case, as a result of the use of rail and as the result of export of the crude to other markets.”

Oliver said Canada has a "strategic need" to diversify its energy export markets.

"Canada will continue to aggressively pursue new markets for oil exports to ensure the Canadian energy industry can take advantage of opportunities in some of the world’s fasted growing economies."

Oliver said that in his meeting with Moniz, he highlighted Canada’s efforts to reduce greenhouse gas emissions in the development of the oilsands.

He said the face-to-face meeting was part of an ongoing dialogue about the two countries' energy and environmental commitments.

"Secretary Moniz was as enthusiastic as I am to enrich our energy dialogue,” Oliver told CTV’s Power Play on Monday. “We have not only the biggest commercial relationship in the world… but also the largest energy relationship."

The topic of Monday’s meeting, however, did not touch on exactly when U.S. President Barack Obama will unveil his decision on the $7.6-billion project -- a decision that will determine the fate of the pipeline and whether it will be carrying more than 800,000 barrels a day from the Alberta oilsands to the U.S. Gulf Coast.

"No, we didn’t talk about the timing. It’s not his direct decision responsibility," Oliver said. "But (Moniz) is one of the eight secretaries who will be consulted."

It is widely expected that Obama will make his decision on the pipeline by the end of this year, or early next year, almost a decade after TransCanada Corp. first proposed the project.

Obama has maintained that he won’t issue the permit which the Calgary-based energy giant needs to build the pipeline if it would significantly worsen global warming.

Monday’s visit with Moniz comes days after reports surfaced that Prime Minister Stephen Harper sent a letter to Obama in August, pledging to work together to curtail carbon emissions in the oil and gas industry.

When asked about the existence of the letter, Oliver said he couldn’t comment on it, but said that what is reported to be in the memo is "consistent with what we want to do."

"(We want) to beef up our relationship of co-operation and collaboration on a whole host of issues, including very specifically the development of non-conventional energy resources."

Meanwhile, environmentalists on both sides of the border have been ramping up their efforts to kill the Keystone XL project, including a leading American critic who recently launched a series of ads across the U.S.

In the ad, funded by NextGen Climate Action billionaire and founder Tom Styer, an actor plays a highly animated CEO of the Calgary company -- a character which is portrayed as a sinister businessman.

"Keystone is only going to drive the price of oil up," says the actor in the ad while sliding down a pipeline filled with oil.

In the one-minute ad, dubbed "Bringing Down TransCanada’s House of Cards: The Keystone Chronicles," it claims that the multi-billion-dollar project will not benefit the American economy. Instead, it says that Keystone crude will be refined and sold offshore to countries such as China.

Oliver said the Canadian government plans on countering the campaign with the "facts."

"We’ve heard a lot of exaggerated rhetoric and sometimes distortion and misinformation and it’s very important, in the Canadian interest that we counter misinformation with the facts."

Canada’s NDP environment critic Megan Leslie, however, says she is doubtful of Ottawa’s ability to deliver those facts.

"It would be hard for (Oliver) to have any information at all after his government got rid of all the scientists at Environment Canada," Leslie told CTV’s Power Play from Saskatoon.

Last year, Environment Canada laid off approximately 60 employees, including senior engineers, environmental compliance officers and climatologists. According to the Professional Institute of the Public Service of Canada, the decision reflects Ottawa’s commitment to the bottom-line, rather than the “protection of Canadians."

"While the government pays lip service to protecting the interests of all Canadians, it continues to target science-based departments, the front line when it comes to protecting the environment and the health of our citizens," Gary Corbett, president of the institute said in a news release.