Canada's prime minister says he "won't take no for an answer" if the Obama administration rejects the controversial Keystone XL pipeline to the U.S. Gulf Coast.

Prime Minister Stephen Harper addressed the Keystone XL project, a flashpoint in the debate over climate change, during a visit to New York City. The long-delayed project carrying oil from Canada's oil sands needs approval from the U.S. State Department, and Harper's remarks are some of his strongest to date.

Harper said Thursday that "this won't be final until it's approved and we will keep pushing forward." He made the remarks at a Canadian American Business Council event.