The meeting in Brussels had been expected to focus on how the EU would reach its goal of cutting carbon dioxide emissions by 20 percent by 2020, but was overtaken by failing banks, plunging stock markets and warnings of recession.

The 27-nation bloc hopes to lead the world in battling global warming, mindful of UN predictions of more extreme weather and rising sea levels.

Eastern European countries and some of Europe's traditional industries say the plan is too costly in light of the crisis, but several EU leaders said that rescuing the economy and the planet could go hand in hand.

"It is not time for the EU to go backwards, we have to be the frontrunners," Finnish Prime Minister Matti Vanhanen said. But east European countries called for the rest of the EU to recognise their economic difficulties, in a statement signed by Poland, Hungary, Bulgaria, Estonia, Latvia, Lithuania, Romania and Slovakia. Poland threatened to veto a December deadline for adopting the climate change plan unless it is altered to shield the coal-based Polish economy from the cost of emissions cuts.

"It is a difficult poker game in which Poland is ready to present its veto if there are attempts to force us into agreement on the climate package next month," Foreign Minister Radoslaw Sikorski told Reuters. "We cannot agree to that." Italy called for more flexible ways of reaching the goals.

Prime Minister Silvio Berlusconi called the whole idea of trading in the right to pollute "ridiculous" and told reporters: "I am ready to use our veto powers." He said he thought leaders would agree to put climate negotiations on hold for a while.

The move to a new economy could create opportunities for European companies, French Prime Minister Francois Fillon said. "What is at stake is a competition worldwide over who will be the leaders -- which companies will bring the most effective products to market first, at the right time and the best price." European employment chief Vladimir Spidla said jobs lost in Europe's older industries could be balanced by jobs created in new green industries -- such as wind turbines or electric cars.

Some leaders linked the climate change battle to EU efforts to reduce the bloc's dependence on oil and gas imports. Energy security has soared to the top of the EU agenda since Russia's invasion of Georgia highlighted the frailty of a key transit route for gas to enter Europe from the Caspian region -- a route aimed at improving the EU's range of energy choices.

British Prime Minister Gordon Brown said Europe's move to a low-carbon economy would help reduce costly and volatile oil imports and protect it from sudden disruptions to supply. "If the last year showed anything, it is that we must deal with the climate change problem, because oil is less affordable than it was, because energy security is more important than it was," he said.

Italy's minister for EU affairs, Andrea Ronchi, said Italy agreed with the bloc's target for cutting CO2, but wanted more flexibility in how to achieve that goal cost-effectively.