Canadian Environment Minister Jim Prentice said on Friday that the United States and other big greenhouse gas emitters will need to agree on steps to cut emissions, and said Canada would harmonize its policies with its big southern neighbor.

In the prepared text of a speech delivered in Edmonton, Alberta, Prentice said Canada still hopes to reach a climate change agreement at international talks slated for Copenhagen next month.

However, he expects no deal can be reached without the backing of the United States, the world's largest economy and a major source of greenhouse gas emissions.

"Canada will continue to work ... with our international partners to lay the foundation for a new international framework for dealing with climate change," Prentice said. "For that to happen, we need the United States on board."

Few countries expect a deal to be reached at the Copenhagen talks, with United Nations officials saying earlier this week that an agreement was unlikely until the middle of next year.

Prentice said he hopes the talks at least establish core principles that will shape any future agreement. However, he added that stabilizing greenhouse gas emissions at non-dangerous levels will require the co-operation of the U.S. and other major emitters, such as China and Europe.

A bill recently passed by the U.S. House of Representatives set a target of reducing greenhouse gas emissions by 17 percent from 2005 levels by 2020, and by 83 percent by 2050.

The U.S. Senate is considering a similar plan and Prentice said a commitment by Washington to cut emissions is crucial to establishing Canada's own plans.

"If the U.S. does not make a substantial effort going forward, there is nothing Canada can do," he said. "Our own mitigation efforts will be futile."

Canada will look to harmonize its emission-reduction targets with the United States and plans a similar "cap and trade" system and an eventual North America carbon market.