The pledge, made at the end of the Group of 20 summit in Australia, comes on the heels of an announcement by U.S. President Barack Obama that the U.S. is contributing $3 billion to the Green Climate Fund.
"We want to see and we will be part of an international agreement of binding obligations on all major emitters," Harper told a news conference after praising the recent climate deal signed between the U.S. and China.
"For the first time, that is actually starting to take shape so that's something we welcome and something we'll contribute to .... we've always contributed to these international climate financing initiatives, and we'll announce our own contributions to it in the not-too distant future."
Canada has long insisted it will follow the U.S. lead on climate change policy, but Harper didn't say how large Canada's own contribution to the fund will be.
Obama's pledge was followed by one from Japan, which announced a $1.5 billion contribution. The two countries issued a joint challenge for other countries to step up with their own contributions to the fund.
Harper hasn't committed to more ambitious greenhouse gas emission targets after Obama and Chinese President Xi Jinping signed their deal, which would result in the U.S. slashing emissions by 26 per cent over the next 11 years. Booming China will stop the increase in its emissions by 2030.
Canada, meantime, is falling short of meeting its own targets to cut emissions by 17 per cent from 2005 levels by 2020.
Obama was insistent that his fellow G20 leaders address climate change at the Australian summit, evidently determined to make climate change policy a priority in his final two years in office.
Australian Prime Minister Tony Abbott, a climate change skeptic and the summit's chairman, had wanted the meeting's primary focus to be on global job creation and economic growth.
Nonetheless the final G20 communique from the leaders addressed climate change. The leaders agreed to spur "finance for adaptation and mitigation, such as the Green Climate Fund."
As Obama prepared to depart the summit on Sunday, he was asked yet again about the fate of the long-delayed Keystone XL pipeline project.
As he's said for the past few years, the president said a determining factor is whether the Trans-Canada pipeline will contribute to global warming.
"One major determinant whether we should approve a pipeline shipping Canadian oil to world markets, not to the United States, is does it contribute to greenhouse gas emissions that are causing climate change?" Obama said.
Also on Sunday, the G20 leaders finalized a plan to boost global GDP by more than $2 trillion over five years by investing in infrastructure and increasing trade.
The communique issued at the conclusion of the summit said the leaders plan to jump-start growth, in part, by creating a global infrastructure hub.
The plan will purportedly help match potential investors with projects, and also help reduce the gap between male and female participation in the workforce by 25 per cent by 2025.
Abbott said countries will hold each other accountable by monitoring implementation of their commitments to boost growth. He noted the leaders unanimously agreed that expanding global trade would directly benefit countries and people around the world.
Despite a communique heavy on economics, Vladimir Putin overshadowed much of the two-day summit and put Harper in the international spotlight for telling the Russian leader to "get out of Ukraine" at a private leaders' retreat.
Harper warned that if the world community eases up on Russia for its annexation of Crimea earlier this year, it will only whet Putin's appetite for similar aggression.
"We send the message, as I think we have in Canada, that whether it takes, five months or 50 years, we're not going to drop the subject until Ukrainian territory is returned to Ukrainians," he said.
"It is necessary for all of us to keep the pressure on Mr. Putin and his regime and to do so over the long term, to make it clear that it will not be business as usual."
-- With files from The Associated Press
Follow Lee-Anne Goodman on Twitter @leeanne25