Harper is taking back the podium from Foreign Affairs Minister John Baird at the world body's largest annual gathering when the General Assembly meets during the week of Sept. 22 at the UN's New York City headquarters.
Over the years, the Harper government has had an uneasy relationship with the UN, and the prime minister has faced accusations of shunning the world body. This month's address will be just his third since coming to power in 2006.
The Prime Minister's Office said Wednesday Harper will also be attending a special UN event hosted by Secretary-General Ban Ki-moon on the health and welfare of pregnant women, newborns and young children in the developing world, titled 'Every Woman, Every Child.'
Harper's office said he and Ban spoke by telephone Wednesday morning to discuss the upcoming events.
The maternal newborn child health initiative is Harper's signature foreign aid priority, and Ban gave it a ringing endorsement this past May when he attended the prime minister's special conference on the subject in Toronto.
"He will go there and speak to his priorities," said one government official, who was not authorized to speak on the record ahead of Harper's address.
"We know he's taken a very strong stand on issues like what's happening in Ukraine, issues like the threat presented by ISIL and certainly in the context of 'Every Woman Every Child,' the prime minister would be expected to speak to that as one of Canada's priorities."
Canada has joined the international effort to curb the offensive by the extremist group the Islamic State of Iraq and the Levant, known as ISIL, which has seized territory across northern and western Iraq and Syria.
Canada has contributed two military transport aircraft to drop humanitarian supplies in Iraq as well as weapons to help arm Kurdish fighters who are trying to stave off the ISIL advance.
Harper has said Canada won't contribute any weapons of its own. But last week — just as Baird had finished his whirlwind tour of Iraq with opposition MPs — Harper announced that he planned to send a small team of military advisers and special forces to Iraq.
The deployment is to be reviewed every 30 days, but Baird suggested this week that the fight against Islamic extremism could take years, calling it "greatest struggle of our generation."
NDP Leader Tom Mulcair said Wednesday that Canada should focus its efforts on humanitarian aid, not military assistance — and he warned against seeing the deployment as anything but Canadian soldiers in Iraq.
"We are not being asked to play a military role," Mulcair said. "I think we've got to avoid word plays where somehow you have members of the military on the ground but you don't have boots on the ground."
On the continuing crisis in Ukraine, Harper and his government have been among the most vocal critics of Russian President Vladimir Putin. Harper has accused Putin of backing the Russian separatists in eastern Ukraine, and called him a threat to world peace.
Harper's UN speech will give him the opportunity to criticize the Security Council as ineffective in responding effectively to these security threats, said Fen Hampson, the director of Global Security at the Centre for International Governance Innovation in Waterloo, Ont.
And it will give him a chance to hit back at critics who say Harper has snubbed the UN, including former prime minister Brian Mulroney, who blasted the prime minister on that front in a televised interview last week.
"It's an opportunity for him to deliver a major foreign policy address," said Hampson.
"Particularly in light of the backhanded comments of Brian Mulroney last week, who joined those who said the prime minister is turning his back on the UN, this is an opportunity for the prime minister to show, it ain't so."
Also during the busy UN week, Environment Minister Leona Aglukkaq will represent Canada at the United Nations Climate Summit.
Harper will also join Ban at a special dinner to discuss climate issues, the Prime Minister's Office says.
Canada has faced strong international condemnation for not doing enough to curb greenhouse gas emissions. Mulroney also piled on last week, telling his CTV interviewer that Harper should make the environment a top priority because it is a "middle class value."
But Harper and his officials aren't worried about facing criticism on climate change after he and Aglukkaq arrive in New York.
"We have, the minister has, and certainly other ministers have been out and defended Canada's record on climate change and pointed to some of the very concrete things we've done," the official said, without elaborating.
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