Representatives from nearly 200 countries have gathered in Durban, South Africa for a U.N. conference on climate change.

The 12-day meeting began Monday and will focus on efforts to extend the Kyoto Protocol, which is set to expire next year.

The Kyoto pact committed industrialized nations to reducing greenhouse gas emissions by a set amount by 2012, but efforts to negotiate its successor have been on hold since the failure of the climate conference in Copenhagen two years ago. Few believe this conference will result in a new agreement, but delegates said Monday they are hopeful.

Tanzania's Richard Muyungi said he thinks the countries can overcome the challenges of the debate.

Meanwhile, Bolivia's Diego Balanza said delegates have to move past the previous climate conference failures.

He said delegates must push to secure large commitments, which were not achieved by prior talks.

Previous efforts have focused on how to balance the responsibilities of developed nations with those of emerging and still-developing countries.

The conference will also consider ways to raise $100 billion a year for the Green Climate Fund, which aims to help countries cope with global warming.

The world's two biggest polluters, the United States and China, will likely be a focus of the talks.

Earlier this month, U.S. President Barack Obama said the United States will use the meeting to urge emerging economies to do more to address global warming. Mr. Obama warned that “advanced economies can't do this alone.”

But last week, China called on developed nations to shoulder the responsibility of substantially reducing carbon emissions, saying they should be accountable for their greenhouse gas emissions during the past 200 years, and that developing nations lack the resources to take the same steps.

The U.S. never ratified the Kyoto pact, and has insisted any legally-binding agreement must also include developing nations.