The meeting of the UN Framework Convention on Climate Changeagreed to launch negotiations on extending Kyoto beyond 2012, when its current commitments for curbing greenhouse-gas emissions expire.

That was complemented by a roster of important decisions that completed the last remaining pieces of the treaty institutional machinery.

Adding the cherry on the cake was an agreement to launch a "dialogue" under the UNFCCC on long-term emissions cuts with the United States, the world's biggest carbon polluter and Kyoto holdout, and with developing countries.

"Now humanity is equipped to face the worst ecological dangers that it has to face in this century," declared the conference's chairman, Canadian Environment Minister Stephane Dion.

The deal came after a night of anger and arm-twisting in which the United States backed down in its opposition to the "dialogue" and Russia was faced down in a last-minute demand that, if conceded, would have destroyed the conference and possibly the Kyoto process as well.

Canadian Prime Minister Paul Martin called the UN climate summit "successful" and said it gave new momentum to international efforts to address global warming.

"Today marks a critical and important point," Martin said. "The successful conclusion of the 11th Conference of the Parties of the UNFCCC and the first Meeting of the Parties to the Kyoto Protocol gives new momentum to taking action on what is clearly a significant environmental challenge for all people of the world and for future generations."

The outcome was greeted with joy by the European Union (EU), which has dived in several times to save Kyoto over the past four years.

British Prime Minister Tony Blair said the agreement was only a beginning, "but it is important and demonstrates why it is always worth engaging with America and the rest of the world."

British Environment Secretary Margaret Beckett, whose country is current EU chair, added the Montreal meeting would give an "essential signal" of support for the fledgling international market for trading in carbon dioxideemissions.

The trading system was launched under Kyoto's format, in which legally-binding limits on CO2 levels are used to drive market incentives for reducing the pollution.

European Environment Commissioner Stavros Dimas said: "Not only did we successfully implement and improve the Kyoto Protocol, more importantly we gave it a future."

Green groups poured vitriol over two familiar foes at the Montreal talks -- the United States and Russia, which have been accused of trying to wreck every climate-change talks for the past four years.

"As expected, the Bush administration attempted to derail the process, at one point even walking out of the negotiations, but the rest of the world showed a will to move ahead regardless," Greenpeace International's Bill Hare said.

"For once, the Bush administration was forced back to the table and into agreement with the international community."

For the World Wide Fund for Nature (WWF), the outcome "displayed the groundswell of support for real climate action... the attempt by the US, and later Russia, to scupper the talks failed when a broad coalition including major developing countries, Japan, Canada and the EU, rebuffed."

"Kyoto thrives in Montreal, despite (a) last-minute game of Russian roulette," Friends of the Earth International said in a press release.

Elation at Kyoto's latest great escape mixed, however, with prudent reminders that the next few years will be fraught with challenges.

Kyoto countries next year will have to sketch the outlines for the post-2012 negotiations -- another political minefield -- and industrialised nations that have ratified the treaty must prove their good faith by meeting their own emissions pledges, said WWF's Jennifer Morgan.

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