CANCUN, Mexico (Reuters) - Old splits between rich and poor nations re-emerged on Tuesday over a plan to slow global warming, but both sides maintained a “balanced package” is the goal of U.N. talks in Mexico.

Children look for recyclable materials from Managua's municipal landfill November 29, 2010. A bloc of left-wing Latin American nations will push lofty goals at world climate talks this month but without the fireworks they set off during the failed negotiations in Copenhagen last year. Venezuela, Cuba, Bolivia and Nicaragua all refused to sign the final Copenhagen Accord in December 2009, saying it was not ambitious enough and was cooked up secretively by big powers. With the next round of climate negotiations in the Mexican resort of Cancun from Nov. 29 until Dec. 10, the left-wing Latin American bloc is once again set to play a high-profile role in the quest for a binding pact to slow global warming. REUTERS/Oswaldo Rivas

After an opening day largely dominated by ceremony, almost 200 countries showed little sign of compromise on past demands that have brought deadlock since last year’s Copenhagen summit fell short of a binding U.N. climate treaty.

All sides stress that Cancun has to come up with a “balanced package,” a mantra that masks deep splits in strategy about how to curb greenhouse gas emissions and divide the responsibilities between rich and poor nations.

“A balanced package means many different things to developed and developing countries here,” said Tim Gore of the humanitarian organization Oxfam. He said there was a risk that some nations might hold the talks hostage to push their agendas.

Developing nations at the two-week meeting reiterated calls for the rich to give 1 percent of their gross domestic product in aid -- far above a deal from Copenhagen that they provide $100 billion a year starting in 2020.

The United States and the EU, by contrast, insisted that “balance” means stronger action by emerging nations like China and India to curb their soaring greenhouse gas emissions by 2020 and to allow more oversight of their actions.

Delegates hope for compromise, noting that there are lower expectations for the Cancun talks than last year’s Copenhagen Accord, which failed to draft an all-encompassing deal to help slow floods, droughts, heatwaves and rising sea levels.

“Not all of our demands are satisfied by current documents. But we think there can be agreement,” said Peter Wittoeck, of Belgium, which leads the European Union delegation in the Caribbean resort of Cancun.

In Mexico, the United Nations wants agreement on a new “green fund” to help developing nations as well as ways to preserve rainforests and to help the poor adapt to climbing temperatures.

The meeting will also seek to formalize existing targets to curb greenhouse gas emissions.

The talks, which require unanimity to progress, are seeking a successor for the U.N.’s 1997 Kyoto Protocol, which obliges almost 40 developed nations to cut greenhouse gas emissions by at least 5.2 percent below 1990 levels by 2008-2012.

The United States never joined Kyoto, believing it would cost U.S. jobs and excluded developing nations.

A statement by the developing nations in the Group of 77 and China said that a balanced deal would have to involve an extension of Kyoto.

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Kyoto backers say that any legally binding Kyoto extension should also bind the United States to cut emissions, and include climate actions by developing countries.

“We will sternly oppose debate for extending the Kyoto Protocol into a second phase which is unfair and ineffective,” Chief Cabinet Secretary Yoshito Sengoku told a news conference in Tokyo on Tuesday.

In Cancun, Bolivia’s delegate Pablo Solon said he was “deeply worried” by reluctance to extend Kyoto, accusing rich nations of rolling back on past commitments.

Failure to agree a modest package in Cancun would raise doubts about the future of Kyoto beyond 2012. Kyoto’s mechanisms encourage a shift to renewable energies from fossil fuels and help guide carbon pricing.