A top UN environment official said Friday that fundamental differences remain among countries negotiating a new agreement on carbon emissions, and that he is concerned over the possibility of bridging those gaps. Achim Steiner, executive director for the UN Environment Program, said that discussions at an environment meeting in Sicily were among the "most frank" he has seen and largely focused on sticking points "where fundamental differences remain to be overcome." Environment ministers from the Group of Eight developed nations and emerging economies, as well as representatives from the EU and the United Nations met for three days in a medieval castle to talk about biodiversity and climate change. The meeting in the eastern Sicilian city of Siracusa was intended to lay some groundwork ahead of a crucial UN conference in December in Copenhagen. That gathering aims to replace the 1998 Kyoto Protocol and draft a new agreement to regulate carbon emissions. The Kyoto Protocol expires in 2012.