Canada's energy minister shot back on Friday at Hollywood celebrities protesting a plan to build a $7 billion oil pipeline to Texas from Alberta in the first public indication that the protests are getting under Ottawa's skin.

Joe Oliver, the minister in charge of energy, said increasingly vocal critics opposing the project on environmental grounds may become a threat to his government's plans to cement Canada as the dominant North American energy supplier.

Criticism of the oil sands - and now the proposed Keystone XL pipeline - is a major concern for us, with implications for our energy industry, our economy and our energy security, Oliver told a business audience in Toronto.

Actors Daryl Hannah and Mark Ruffalo, author and environmentalist Bill McKibben, No Logo author Naomi Klein, as well as the Dalai Lama and Desmond Tutu are among notables who have come out against the Keystone XL pipeline.

Hannah was one of more than 1,200 people arrested in protests against Keystone XL at the White House in August and September. Another anti-oil sands demonstration is planned for Ottawa on September 26, and a host of Canadian actors, including Gordon Pinsent and Dave Thomas, have said they back the cause.

Still, Oliver insisted he does not believe that protests will derail development of the pipeline.

I remain optimistic about the ultimate decision that the government of the United States will make in the national interest, as they see it, he told reporters at the event. But we don't presume to interfere with their permit processing.

In his speech, Oliver listed several initiatives the oil industry and the government have undertaken to improve environmental performance in the Alberta oil sands, including reclaiming land and reducing greenhouse gas emissions.

He stressed that mines in the tar sands have displaced only 0.1 percent of the country's boreal forest. You won't hear this from celebrity protesters, he said.

Prime Minister Stephen Harper's Conservative government has been an enthusiastic promoter of TransCanada Corp's Keystone XL pipeline, which would ship more than half a million barrels a day of oil sands-derived crude to Texas from Alberta.

Until now, ministers have steered clear of mentioning big-name protesters, saying only that they are confident the U.S. State Department will ultimately approve the project.

Opponents say the pipeline will put vast underground water supplies in the United States at risk of oil spills and foster more oil sands production, which emits more carbon dioxide than conventional oil production.

Oliver said the celebrities are not considering the facts of the issue, including the need to improve North American energy security with the help of Canada's vast resources.

Canada has excess capacity, and the U.S. has excess demand. So we need a pipeline that will transport as much as 700,000 barrels a day of Western crude from Alberta to the refineries in Texas, where it is needed, he said.

Oliver also highlighted efforts to diversify the customer base for Canadian oil through the development of Enbridge Inc's Northern Gateway pipeline, a project also opposed by environmentalists as well as a host of British Columbia aboriginal groups.

That proposed C$5.5 billion ($5.3 billion) line, which has yet to go to public hearings, would connect the oil sands to a Pacific Coast port at Kitimat, British Columbia, where oil could then be shipped to Asia.

Currently, 97 percent of Canadian oil exports go to the United States.

It is critically important for us to diversify our customer base, Oliver told reporters. We hope to be an increasingly important supplier of energy to China.

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