BRUSSELS, Sept 18, 2009 (AFP) - EU leaders on Thursday put pressure on the United States and other rich nations to provide at least five billion euros of "fast-start" money next year to help poor nations tackle climate change.

The call came as European heads of state and government held a summit in Brussels aimed at forging a joint position ahead of the G20 summit of major and developing economies in Pittsburgh next week.

"The G20 should recognise the need to fast-start international public support for addressing urgent climate financing needs in developing countries," the EU leaders agreed in a statement.

The European Commission estimates that five to seven billion euros annually will be needed in the 2010-2012 period until a more long-term "financial architecture" is put in place, hopefully, at a UN climate conference in Copenhagen later this year.

The commission says that the annual figure needed to help developing nations combat and deal with climate change will hit 100 billion euros (147 billion dollars) per year by 2020.

"It's time for a wake-up call to world leaders on climate," said Swedish Prime Minister Fredrick Reinfeldt, who presided over the Brussels summit.

The United States and the rest of the world are not doing enough to tackle climate change at a time when "the world has a fever," he said.

"We really need to step up, stop the acting and start delivering action.

"The negotiations are going too slowly. The (emissions) reductions targets presented by different countries are not enough for us" to meet a target to keep global warming at no more than two degrees Celsius above historic levels, Reinfeldt told reporters.

EU heads of state and government agreed in their summit statement that "the climate is changing much faster than expected. The risks posed by climate change are real and can already be seen."

Therefore it is vital to reach an ambitious global agreement at UN climate talks in Copenhagen, the 27 heads of state and government agreed.

British Prime Minister Gordon said the 100-billion-euro figure had been his proposal.

He dismissed reluctance on the part of France, Germany and others to fix global climate aid targets saying: "You cannot get a climate-change deal without an agreement on finance."

Eastern European member states are also keen to talk first about how funds will be distributed within the EU.

The European Union prides itself on being at the forefront of the climate fight.

The 27 nations have committed to reducing total greenhouse gas emissions by 20 percent by 2020, from 1990 levels.

At Copenhagen they will be seeking a global deal for 30 percent cuts.