DURBAN, South Africa - Canada's environment minister has praised the agreement on climate talks reached in South Africa on Sunday, and said he was cautiously optimistic a new treaty can be concluded by 2015.

"The Durban Platform is a fair and balanced framework for responsible and effective action," Peter Kent said.

Earlier in the day, the 194-party conference in Durban agreed to start negotiations on a new accord that would ensure that countries will be legally bound to carry out any pledges they make.

It would take effect by 2020 at the latest.

"Although these negotiations will be difficult, we are cautiously optimistic that we will reach a new agreement by 2015." Kent said.

The minister also reiterated his opposition to the 1997 Kyoto Protocol, saying the deal was not good for Canada, and the previous government should not have ratified it.

"We want to avoid another Kyoto-like pact at all costs."

Currently, only industrial countries have legally binding emissions targets under the Kyoto Protocol.

Those commitments expire next year, but they will be extended for at least another five years under the accord adopted Sunday — a key demand by developing countries seeking to preserve the only existing treaty regulating carbon emissions.

Kent, who came to Durban saying Kyoto represents the past, declared Sunday that Canada would not undertake a second Kyoto commitment period.

"Nor will we devote scarce dollars to capitalize the new Green Climate Fund _ part of the Durban agreement _ until all major emitters accept legally binding reduction targets and transparent accounting of greenhouse gas inventory."

But he promised to work with Canada's international partners on "fair, effective and comprehensive ways" to address climate change.

In Vancouver, the Pembina Institute's climate change program welcomed the Durban agreement.

"The decision to launch talks on a new global climate agreement with legal force represents a potentially significant step forward," said Matt Horne, director of the program.

"But a new deal will only be as effective as the level of ambition that countries are willing to bring to the table," he warned.

He said Canada was marginalized at Durban because of the country's failure to present constructive solutions or meaningful action.

"Our country has regrettably passed up countless opportunities to demonstrate a willingness to do our fair share."

He said restoring Canada's credibility will take hard work.

"It will require much stronger actions from federal, provincial, and municipal governments if clean energy is going to become the status quo."

Meanwhile, the Ottawa-based International Climate Science Coalition has rejected the accord. The group also challenged claims that developed countries are somehow responsible for global warming.

"Developed nations are not guilty of causing the climate change that developing nations claim they are suffering," said Tom Harris, executive director of the group.

At the Durban conference, India's environment minister had argued that developing countries have less responsibility than industrial nations for global warming.

"Climate changes all the time, both warming and cooling, due to natural causes and there is nothing that we can do to stop it," Harris said.

"However, to the degree possible, and considering our economic circumstances, developed nations still have a moral obligation to devote a proportion of their foreign aid to helping the world's most vulnerable people adapt to natural climate events."