Mexican President Felipe Calderon on Monday called for financial help for developing countries to meet their climate change commitments under a new treaty set to replace the Kyoto Protocol.

The Major Economies Forum (MEF), including environment ministers from the world's largest polluters, met in central Mexico Monday as part of a US push to speed up work towards the key new United Nations accord to curb greenhouse gases.

The new agreement must include "adequate instruments so that all the world's nations, particularly developing countries, can count on sufficient (economic) stimulus and incentives to meet their commitments," Calderon said at the start of the two-day meeting.

"We have to break certain patterns, certain old ways of thinking," Calderon added, referring to Mexico's recent promise to reduce carbon dioxide (CO2) emissions by 50 million tonnes per year -- the first developing country to make such a unilateral commitment.

The group's third meeting in as many months comes as worldwide climate negotiations are stalling ahead of a major Copenhagen summit in December aimed at producing the new UN accord.

Twelve days of international climate change talks ended last week in Germany without progress on the biggest question of how to share the burden of future emissions cuts.

Poor nations are seeking deep cuts from rich countries which are historically most to blame for today's problems.

They are mostly calling for cuts of around 25 to 40 percent by 2020 compared with 1990 levels. Some countries, including China, have said 40 percent must be a minimum.

Within industrialised nations, the European Union (EU) has offered a cut of at least 20 percent from a 1990 baseline, but Japan and the United States have so far offered reductions of only around eight percent and four percent respectively.

The MEF was launched by US President Barack Obama on the back of a similar initiative by his predecessor, George W. Bush.

Participants include Australia, Brazil, Britain, Canada, China, the Czech Republic, Denmark, France, Germany, India, Indonesia, Italy, Japan, South Korea, Mexico, Russia, South Africa, Sweden and the United States, as well as the 27-nation European Union.

The talks come as international support is growing for a Mexican proposal to raise billions of dollars to fight climate change through a so-called "Green Fund."

The plan would oblige all governments to pay in cash based on a formula reflecting the size of each nation's gross domestic product, greenhouse gas emissions and population.