A United Nations climate conference continued through the night Friday with nations still facing deep divisions on how to cut greenhouse gases.

After two weeks of negotiations in Durban, South Africa, delegates struggled with the details of a European Union proposal to create a binding pact to fight global warming.

Observers say the world's biggest emitters, including the United States, China and India, have yet to agree to the proposal.

The Europeans won critical support on Thursday from an alliance of the world's poorest countries and small island nations. The EU has indicated that the world's biggest polluters have been slowing down the pace of the negotiations.

The EU plan sets a 2015 target date for an agreement that would bind all nations to legal commitments to tackle greenhouse gases. The EU has said it will not renew its emissions reductions pledges under the Kyoto Protocol unless all countries are committed to controlling their emissions.

The United States has previously said it will only pledge binding cuts if all major polluters make comparable commitments. China and India have said that their level of cuts should be less than those of developed nations. None of those three countries is bound by the Kyoto Protocol.