A climate deal brokered by President Barack Obama with China and other emerging powers is being bogged down by arguments between delegates in a plenary session.
Several countries, including Bolivia, Venezuela and Sudan say the document is unacceptable because it lacks targets for reducing carbon emissions.
Sudan's delegate Lumumba Di-Aping said it would condemn Africa to widespread deaths from global warming and compared it to the Holocaust. His statement was denounced by other delegations.
Danish Prime Minister Lars Loekke Rasmussen, who hosted the conference, says the convention appears to lack consensus, meaning the document cannot be adopted. The debate continued into the early morning hours in Saturday.