 The United Nations' top climate change official on Thursday called on Tokyo to push for ambitious midterm emissions targets at the G8 summit to be held in northern Japan in July. Yvo de Boer, in Tokyo for an official level climate change conference, told reporters that Japan faces the task of reaching a consensus among industrialised countries on 2020 targets for reductions in greenhouse gas emissions. "As chair of the G8, Japan could lead the discussion by moving forward on ambitious midterm targets," said de Boer, executive secretary of the UN Framework Convention on Climate Change. "The world, especially the private sector, is looking for clarity on this." De Boer added that there was already broad agreement that industrialised countries should think in terms of cuts of 25-40 percent from 1990 levels by 2020 and that emissions should peak in the next 10-15 years. "The challenge will be to see if the G8 summit under the Japanese presidency can identify where the G8 countries want their emissions to be in 2020," he said. Japan, one of the world's biggest greenhouse gas emitters, has already flagged climate change as one of the main issues for discussion at the G8 summit on the northern island of Hokkaido. Japanese Prime Minister Yasuo Fukuda told the World Economic Forum in Davos last month that Japan was committed to setting a national midterm target beyond the 2012 expiration of the Kyoto Protocol, without specifying what the figure would be. "It is not just a question of giving a figure," Japan's top government spokesman Nobutaka Machimura said when asked about de Boer's comments. "It must be based on rules that everyone can accept. We are about to start discussions on this," he said, but added that the summit would not necessarily be the time limit. At United Nations-led talks in Bali last year, Japan sided with the United States and rejected a European Union-backed emissions cut target beyond 2012, prompting outrage among environmentalists.