WARSAW, Poland -- U.N. climate talks ran into overtime Friday with more than 190 countries arguing over the building blocks for a new pact to slow global warming.
A draft text presented on the last scheduled day of the two-week conference in Warsaw gave only vague direction on when countries should present their targets for restricting carbon emissions. That's a key element of the deal that's supposed to be adopted in Paris in 2015.
Despite a push by the European Union and the U.S. for a clear timeline for announcing targets, the draft text said only that commitments should be presented "well in advance" of the Paris summit.
U.S. climate envoy Todd Stern called for "stronger language" to drive the work forward.
The EU wants to present its target in 2014 and the U.S. is aiming for early 2015 to leave time for a review process before the Paris conference. But some countries, including China, the world's biggest carbon polluter, have been reluctant to set a deadline.
"We should talk, and we should deliver and announce during the process of negotiations," Chinese delegate Liu Zhenmin told reporters. "I don't know when. I cannot say a timeframe."
He suggested that China shouldn't be expected to make emissions cuts on the same level as industrialized countries, which built their economies with fossil fuels. The EU and the U.S. want to get rid of the rich-poor division that has guided the talks in the past, saying China's rapid economic growth means it no longer can compare itself with poorer developing countries.
"This is not the time to go backward and reinstall walls we have been trying to tear down," European Union Climate Commissioner Connie Hedegaard told reporters.
Venezuelan negotiator Claudia Salerno, a spokeswoman for a group of "like-minded" developing countries, including China and India, accused Hedegaard of starting a "blame game" through the media.
"We are shocked by the brazen attack against our group by Connie Hedegaard of the European Commission. It is incredible that she has chosen to accuse our group" of blocking the process, Salerno said in a statement.
The U.N. climate talks were launched in 1992 after scientists warned that humans were warming the planet by pumping CO2 and other heat-trapping gases into the atmosphere, primarily through the burning of fossil fuels. Though governments agree global emissions need to come down, they've been unable to agree on how to divide those cuts.
In Warsaw, negotiators were trying to lay the foundation of a 2015 deal that would take effect five years later, but were bogged down by recurring disputes over who needs to do what, when and how.
Deputy Environment Minister Beata Jaczewska of host nation Poland, predicted a "sleepless night" ahead. "But we are still hoping to close the meeting as soon as possible," she said.
Countries made progress on advancing a program to reduce deforestation in developing countries, an important source of emissions because trees absorb carbon dioxide.
Disputes persisted on climate financing. Rich countries have promised to help developing nations make their economies greener and to adapt to rising sea levels, desertification and other climate impacts.
Island nations that fear being submerged as the seas rise also demanded a new "loss and damage mechanism" to deal with weather disasters made worse by climate change.
Developed countries resisted that proposal, fearing they would be held liable for damage caused by extreme weather events.