Prime Minister Stephen Harper spoke to U.S. president-elect Barack Obama on Thursday, congratulating the Democrat for his election win earlier this week.

"In a warm exchange, the two leaders emphasized that there could be no closer friends and allies and vowed to maintain and further build upon this strong relationship," said an email about the call between the two leaders from the Prime Minister's office.

Sources have told CTV News that the Prime Minister brought up the idea of a continental pact on climate change, which Obama seemed open to.

Before the conversation Harper told reporters in Toronto that Obama's win represented an "era of possibility."

"Obviously the election of the first African-American president is a tremendous and truly inspiring moment, I think, in American political history," Harper said.

Harper said that he would push Canada's agenda in the U.S. as positives for both countries.

"We will be pursuing distinctive Canadian policies but doing so in a way that is helpful to the United States and the world as a whole."

Harper also said that his political team would no doubt be studying the lessons learned from Obama's impressive political campaign strategy. He also congratulated Obama on a hard fought primary against Hillary Clinton.

But he added: "That all said, president-elect Obama is going to face tremendous challenges."

The PMO email about the Obama-Harper conversation on Thursday noted the two leaders "touched on" the G20 Leaders' Summit slated for Washington this month.

"I will tell the president-elect that, for Canada, our most important international relationship is always with the United States for all kinds of reasons, whether it's on environment and energy, the economy and the financial crisis or on international peace and security issues, particularly Afghanistan," Harper had said before the call.

Experts say that Harper stands a better chance of having Obama's ear than other world leaders.

"We are one of the few voices in NATO the Americans are prepared to listen to because we are on of the few in NATO actually doing the heavy lifting in Afghanistan," James Blanchard, a former ambassador to Canada, told CTV's Mike Duffy Live on Thursday evening.

Blanchard added that the fact the two North American leaders appear to have had a good conversation is a promising indicator.

"Every leader in the world wants to talk to Barack Obama. I doubt very many have, so that's a really good sign," he said.

Blanchard said Obama's substantial win on Tuesday may help pave the way for smoother Canada-U.S. relations.

"Obama's going to ride a huge wave of popularity both here, and in Canada, I might add," he said.

He said Obama's popularity here in Canada may help Harper deal more easily with the new White House than it could with the Bush administration, which was unpopular with many Canadians. He said Canadian critics will be less likely to question Harper's closeness to the U.S. under Obama.