NEW YORK, N.Y. - Canada won't "take no for an answer" from the U.S. when it comes to the Keystone XL pipeline, Prime Minister Stephen Harper said Thursday as he sharpened his sales pitch for the controversial cross-border energy proposal.

The logic in support of the project going ahead is "overwhelming," and governments at all levels on both sides of the Canada-U.S. border are endorsing it, Harper told a high-powered business audience in New York.

"My view is that you don't take no for an answer," Harper said. "We haven't had that. If we were to get that, that won't be final. This won't be final until it's approved and we will keep pushing forward."

In his strongest rhetoric on the much-maligned project to date, Harper also dismissed the divide between his government and the White House over projections of how many jobs Keystone XL will create.

"It's just politics," Harper told the audience at the Canadian American Business Council event. There is no real "plan B" for Canada should U.S. President Barack Obama turn down the pipeline, he added.

"The logic here is overwhelming," Harper said.

"I remain an optimist that, notwithstanding politics, that when something is so clearly in everybody's interest — including our interest as Canadians, but the national interest of the United States — I'm of the view that it has to be approved."

A brief editorial that appeared on the New York Times website Saturday accused the Harper government of preventing government scientists from publicly criticizing the project, which is designed to ferry oilsands bitumen from northern Alberta all the way to refineries on the U.S. Gulf Coast.

Harper is bent on ensuring public ignorance by keeping scientists who receive government funding from sharing information, especially climate change research, wrote Verlyn Klinkenborg, a member of the newspaper's editorial board.

Harper has been pushing the Obama administration to approve the Keystone project, insisting that it will create thousands of jobs on both sides of the border.

But American critics of the proposal, including within the White House, have significantly played down the economic benefits of the plan.

Supporters of Keystone XL, including Harper himself, tout it as a major step towards making North America self-sufficient when it comes to energy, eliminating the need to import oil from overseas countries that are politically unstable and less environmentally responsible.

Opponents, however, see the plan as an environmental catastrophe in the making. They worry about bitumen leaking into ecologically sensitive areas. They also argue that Canada's oilsands are major producers of greenhouse gases and urge less production there, not more.

The Keystone XL proposal has been under study for five years, caught in a maelstrom of clashing political, economic and environmental interests.

Earlier Thursday, Day 2 of his trip to New York, Harper met a Pakistani teen who became a champion for girls' education after being shot by the Taliban.

The prime minister sat down with 16-year-old Malala Yousafzai, who was shot in the head by the Taliban last fall, only to recover in a British hospital and become an international figure.

On Wednesday, Yousafzai pleaded with world leaders to use education as a tool, rather than war, as she took part in the first anniversary of the Global Education First Initiative at the UN.

She urged United Nations member states to use books, not guns, in conflict zones.

"Instead of sending weapons, instead of sending tanks to Afghanistan and all these countries which are suffering from terrorism, send books,'' Yousafzai said.

The Prime Minister's Office initially refused to say what Harper and Yousafzai spoke about on Thursday, calling their get-together private.

But an official later said that Yousafzai talked about her efforts to promote education for women and girls, and that Harper invited her to visit Canada.

Harper also spoke over the phone with German Chancellor Angela Merkel to congratulate her on her victory in Germany’s Sept. 22 federal election. A spokesman said the two leaders spoke about the desire to complete a Canada-EU trade agreement.

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  • Dalai Lama

    In September 2011, the Dalai Lama was one of nine Nobel Peace Prize laureates who <a href="http://www.huffingtonpost.ca/2011/09/07/nobel-peace-prize-winners_n_952248.html" target="_hplink">sent a letter to U.S. President Barack Obama</a> urging him "to say 'no' to the plan proposed by the Canadian-based company TransCanada to build the Keystone XL, and to turn [his] attention back to supporting renewable sources of energy and clean transportation solutions."

  • Archbishop Desmond Tutu

    Archbishop Desmond Tutu was among<a href="http://www.huffingtonpost.ca/2011/09/28/nobel-prize-winners-oil-sands_n_985171.html" target="_hplink"> a group of Nobel Peace Prize laureates</a> who signed letters to both U.S. President Barack Obama and Canadian Prime Minister Stephen Harper, urging the men to stop the Keystone pipeline.

  • Al Gore

    Gore has said it is essential to stop the Keystone pipeline because the tar sands oil it would carry is "the <a href="http://www.huffingtonpost.com/al-gore/the-dirtiest-fuel-on-the-_b_944186.html" target="_hplink">dirtiest source of fuel on the planet</a>."

  • Robert Redford

    Actor and environmentalist <a href="http://www.imdb.com/name/nm0000602/" target="_hplink">Robert Redford</a> recently added his name to the list of prominent individuals who are calling on President Obama to reject the Keystone XL pipeline. <a href="http://www.huffingtonpost.com/2011/10/24/robert-redford-keystone-xl_n_1019789.html" target="_hplink">In a video for <em>The New York Times</em>, produced with the Natural Resources Defense Council</a>, Redford described the negative aspects of the proposed tar sands pipeline and said, "By deepening our reliance on oil, the pipeline would be a job killer." Redford has previously been vocal about calling for alternatives to oil. <a href="http://www.huffingtonpost.com/robert-redford/keystone-xl-pipeline_b_978835.html" target="_hplink">Writing last month for HuffPost</a>, he said, "Let's build the next generation of energy efficient cars, homes and workplaces. Let's develop wind, solar and other cleaner, safer, more sustainable sources of power and fuel. Let's invest in high-speed rail and smart communities that give us better transportation options."

  • Mark Ruffalo

    Actor <a href="http://www.imdb.com/name/nm0749263/" target="_hplink">Mark Ruffalo</a>, famous for films like "<a href="http://www.imdb.com/title/tt0842926/" target="_hplink">The Kids Are All Right</a>" and "<a href="http://www.imdb.com/title/tt0443706/" target="_hplink">Zodiac</a>," is also an outspoken activist and opponent of the Keystone XL pipeline. Ruffalo <a href="http://www.huffingtonpost.com/2011/08/11/mark-ruffalo-tar-sands_n_924245.html" target="_hplink">said in a video</a> for the <a href="http://www.tarsandsaction.org/" target="_hplink">Tar Sands Action</a> group, "I've seen the kind of damage that out-of-control energy development can do to water and to communities near my own home, where fracking for natural gas is causing widespread pollution ... All these problems are connected -- we need to get off fossil fuels." In the past, Ruffalo has also expressed his ire for hydraulic fracturing natural gas extraction, or fracking. He told The Huffington Post, "The <a href="http://www.huffingtonpost.com/2011/01/18/mark-ruffalo-fights-frack_n_810461.html" target="_hplink">world is already leaving us behind</a>. We're being left behind. America. Because the gas and oil industry has a strangle hold on us. And our politicians."

  • Bill McKibben

    Environmentalist and author <a href="http://www.huffingtonpost.com/bill-mckibben/" target="_hplink">Bill McKibben</a> has expressed strong disapproval for the planned Keystone XL pipeline. In fact, he was <a href="http://www.tarsandsaction.org/press/releases/aug20/" target="_hplink">one of the first</a> of over 1,200 who were arrested at the Tar Sands Action sit-in at the White House in August. Referring to <a href="http://www.huffingtonpost.com/2011/08/23/keystone-xl-frustrated-environmental-activists-obama_n_933648.html" target="_hplink">his opposition to the Keystone Pipeline</a>, McKibben told HuffPost, "The people who've carried this fight for three years are indigenous people on both sides of the border who have a huge stake in it because it's on their land, and farmers and ranchers from places like Nebraska," he said. He added, "It wasn't until I sat down and read <a href="http://www.huffingtonpost.com/dr-james-hansen" target="_hplink">Jim Hansen</a>'s analysis of how much carbon was in those things that I understood that this was not just a national issue, it's a global issue of the first order."

  • Julia Louis-Dreyfus

    <a href="http://www.imdb.com/name/nm0000506/" target="_hplink">Julia Louis-Dreyfus</a>, known for her role as Elaine on the popular sitcom "Seinfeld," has released a video urging President Obama to reject the permit for the Keystone XL pipeline. Dreyfus recalls when Obama said "Let us be the generation that ends the tyranny of oil." But she says, "Big Oil is still pretty much running the show." She claims that by rejecting the pipeline, Obama has a chance to "make good on [his] word." <a href="http://www.tarsandsaction.org/video-release-julia-louis-dreyfus-challenges-pres-obama-stop-keystone-xl/" target="_hplink">Louis-Dreyfus asks Obama</a>, "Denying the permit for a brutally stupid, money-grab like the Keystone XL pipeline is a no-brainer, right Mr President?"

  • Nebraska Governor Dave Heineman

    Dave Heineman, the Republican governor of Nebraska, has officially stated that he opposes the Keystone XL project. As the governor of an agrarian state through which the pipeline would pass, Heineman expressed his concern for the pipeline's threat to Nebraska's vital water resources. According to the Associated Press, "Heineman said <a href="http://www.huffingtonpost.com/2011/08/31/nebraska-governor-opposes-pipeline_n_943610.html" target="_hplink">he supports pipeline projects</a> but opposes the proposed TransCanada Keystone XL route." In August, Heineman <a href="http://www.governor.nebraska.gov/news/2011/08/31_pipeline.html" target="_hplink">sent an open letter</a> to President Obama and Secretary of State Hilary Clinton urging them to "not allow TransCanada to build a pipeline over the Ogallala Aquifer and risk the potential damage to Nebraska's water."

  • Daryl Hannah

    Actress <a href="http://www.imdb.com/name/nm0000435/" target="_hplink">Daryl Hannah</a> has also lent her voice to the movement against the <a href="http://www.huffingtonpost.com/news/keystone-pipeline" target="_hplink">Keystone XL pipeline</a>. In August, Hannah was one of the over 1,200 people to be <a href="http://www.huffingtonpost.com/2011/08/30/daryl-hannah-arrested-keystone-protest_n_942072.html" target="_hplink">arrested as an act of civil disobedience</a> in front of the White House. Shouting "no to the Keystone pipeline" as she was handcuffed, Hannah made it clear she opposed the proposed Canada to Texas pipeline.

  • Maude Barlow

    Maude Barlow, a Canadian author and activist and chairperson of <a href="http://www.canadians.org/" target="_hplink">The Council of Canadians</a>, was arrested in September at a Keystone pipeline and oil sands protest on Parliament Hill in Ottawa. <a href="http://www.huffingtonpost.ca/2011/09/26/ottawa-oil-sands-pipeline-protest_n_981052.html" target="_hplink">She was one of over 100 protesters</a> of the demonstration's estimated 400 to be arrested. Writing for HuffPost Canada about <a href="http://www.huffingtonpost.ca/maude-barlow/maude-barlow-arrested_b_982487.html" target="_hplink">her first experience being arrested</a>, Barlow blogged, "I did it because I fear we are killing the planet and I can no longer be content to only write and speak about it. Today my feet spoke for me as I crossed that barricade and took away one more fear in my life." She also said, "By investing trillions of dollars into these pipelines, governments and the energy industry are ensuring the continued rapid acceleration of tar sands development, instead of supporting a process to move to an alternative and sustainable energy system."

  • Kyra Sedgwick

    <a href="http://www.imdb.com/name/nm0001718/" target="_hplink">Kyra Sedgwick</a>, star of the television crime drama "The Closer," has voiced her opposition to the pipeline. In a video for the <a href="http://www.nrdc.org/" target="_hplink">Natural Resources Defense Council</a>, Sedgwick said "Just like the BP oil spill, one glitch in the tar sands pipeline could destroy our clean water sources, possibly forever."

  • David Strathairn

    Joining several other prominent actors, David Strathairn appeared in a video urging President Obama to reject the Keystone Pipeline. He calls on his fellow Americans to join the November 6 <a href="http://www.tarsandsaction.org/" target="_hplink">Tar Sands Action</a> in Washington, D.C. <a href="http://www.imdb.com/name/nm0000657/" target="_hplink">Strathairn</a>, who is known for his portrayal of journalist Edward R. Murrow in "Good Night, and Good Luck," said, "Obama ran for office speaking of the dangers of our fossil fuel addiction, promising to fight climate change and fully embrace a clean energy future. The <a href="http://www.huffingtonpost.com/news/keystone-pipeline" target="_hplink">Keystone XL tar sands pipeline</a> is a dangerous step away from that commitment."

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