Canadian Prime Minister Stephen Harper said Tuesday that it's important for the nation to diversify exports to the Asia-Pacific region, but wouldn't be drawn into commenting specifically about Enbridge Inc.'s (ENB) proposed and controversial Northern Gateway pipeline.

A joint review panel is considering the environmental effects of the pipeline's route from Alberta to a port in British Columbia, Canada's westernmost province, to ship oil to China and other buyers in Asia.

Speaking at an event in British Columbia, Mr. Harper said the project has to be approved through an independent evaluation process.

"In a broad sense, without getting into the specifics of any project...we think it's obviously in the vital interest of Canada and in the vital interest of British Columbia - as Canada's Asia-Pacific gateway, the economic growth we expect to have here in the future is going to be based on commerce with the Asia-Pacific region - and we think it's important that we continue to diversify our exports through this province," Mr. Harper said.

B.C. Premier Christy Clark has threatened to block construction of the proposed pipeline if the province's demands, which include financial compensation, aren't met. Alberta Premier Alison Redford has dismissed the demands.

Mr. Harper said he had discussed the matter with Ms. Clark and other premiers but declined to provide details of what he said are private conversations. "Let me just say this though: I'm not going to get into an argument or a discussion about how we divide hypothetical revenues," Mr. Harper said.

He also said the Canadian government will "thoroughly assess" any foreign investments in the country to ensure they are of "net benefit" to Canada," in response to a question about the proposed takeover of Calgary-based oil and gas producer Nexen Inc. (NXY) by China's CNOOC Ltd. (CEO).

"We will be in the process of evaluating (the proposal) when the formality of the process begins," Mr. Harper said, adding he won't say anything that will prejudice the government's decision "one way or another in that regard."

"But I have told people not to assume a particular outcome. The government will thoroughly analyze this from the perspectives of the best interest of the Canadian economy," he said.

Meanwhile, Mr. Harper condemned the killing of six people in at a Sikh Temple in Oak Creek, Wis., Sunday. He said such "wanton and random violence" is "just an absolute outrage," and "I don't think we can condemn it in terms that are ever too strong."

B.C. is home to a significant Sikh population. "We're all outraged by this and we all stand in solidarity with our fellow Sikh citizens in condemning this act and doing everything we can to ensure these kinds of things will not happen in this country," Mr. Harper said.

Write to Nirmala Menon at nirmala.menon@dowjones.com