In Copenhagen, environment ministers worked on bridging the gap between wealthy and developing countries before the approaching deadline for a global agreement on addressing climate change. Yvo de Boer, leader of the UN Climate Change Secretariat, pointed out a disagreement between major greenhouse gas emitters China and the United States, expressing his wish for all countries to increase their efforts in the negotiations. "China is urging the United States to take further action. The United States is urging China to do the same. I hope that in the upcoming days, all nations will encourage each other to do more," he stated. The ministers were engaging in informal discussions during a one-day break in the December 7-18 meeting with 190 nations. This meeting will end in a summit of world leaders on Thursday and Friday, with US President Barack Obama participating. Danish Minister Connie Hedegaard stated to reporters that although there are numerous challenges and unresolved issues, there is a political will among ministers. The discussions involve representatives from both wealthy and developing nations who have been debating over the responsibilities for emissions reductions, the extent of these reductions, and who should provide funding for them. Countries like China and India are calling for the industrialized world to make more substantial reductions in greenhouse gas emissions and provide financial assistance to help poorer nations transition to a more environmentally friendly economy and adapt to the impacts of climate change. Indian Environment Minister Jairam Ramesh expressed optimism about reaching a fair agreement in Copenhagen if there is trust, courage, and conviction among all parties. Wealthier nations argue that developing countries need to limit their carbon emissions to avoid dangerous levels of global warming. China is aiming to reach a solid agreement before Premier Wen Jiabao attends the summit with other world leaders. Senior Chinese envoy Su Wei stated on Saturday that the leaders are expected to come and celebrate the positive outcome of the talks. On Sunday, Archbishop Desmond Tutu delivered thousands of signatures calling for climate action to the UN's de Boer. A church service with a sermon by Archbishop of Canterbury Rowan Williams and attended by Danish royalty was planned at Copenhagen's Cathedral, followed by a global "bell ringing for the climate." Police have released all but 13 of the nearly 1,000 individuals detained after a peaceful march on Saturday, which turned violent in the evening when demonstrators damaged property and set fire to cars. Some individuals who were detained claimed that they were unjustly held and mistreated by the police. Hana Nelson, a 24-year-old student from Halifax, Canada, who was released without charges, stated, "They arrested us without cause. We were all peaceful."