As U.N. climate talks entered their final stage Thursday in South Africa, delegates were struggling with how to accommodate the desire of many nations for a new, legally binding treaty and the Obama administration’s resistance to such a commitment.

The nearly 200 nations participating in the U.N. Framework Convention of Climate Change negotiations remain divided on three central questions: whether industrialized nations will embrace new climate targets under the existing 1997 Kyoto Protocol; how to move forward on establishing a broader global warming pact; and how to administer international assistance to poor nations hard hit by climate issues.

The European Union has called for a “road map” that would outline negotiations aimed at reaching a legally binding treaty by 2020 or earlier. Although the Obama administration has resisted the idea of signing onto a process that will automatically lead to a legal deal, U.S. special envoy for climate change Todd Stern told reporters Thursday that when it comes to a road map, “We support that.”

“It is completely off base to suggest that the U.S. is proposing that we delay action until 2020,” he said.

But afterward, State Department spokeswoman Emily Cain issued a statement making it clear the U.S. negotiating position remained unchanged: “Todd Stern said in his press conference today that the United States could support a process to negotiate a new climate accord. He did not say that the United States supports a legally binding agreement as the result of that process.”

Delegates were considering alternative wording to get around “legally binding,” including referring to a “multilateral rules-based system.”

Dessima Williams, Grenada’s representative to the United Nations who chairs the Alliance of Small Island States, said the world’s major greenhouse gas emitters must agree to forge a new climate treaty before 2020 or risk disastrous climate consequences. Officials from developing countries emphasized that delegates must also reach a consensus on how to operate the Green Climate Fund.