TOYAKO, Japan, - The United States and Japan called Sunday for urgent action on red-hot oil and food prices that could derail the global economy on the eve of a summit of the world's richest nations. Group of Eight leaders will hold three days of talks, starting from Monday (today), in the resort town of Toyako that will be dominated by the fragile world economy, global warming and problems ranging from Zimbabwe to North Korea and Iran's nuclear ambitions. Bush met with Japanese Prime Minister Yasuo Fukuda that also touched on a host of issues including climate change and aid to Africa. Fukuda said the leaders of the world's two largest economies had agreed that urgent efforts are needed to tackle surging oil and food prices. The dual-crises "are having a negative impact on the world economy," Fukuda told a joint Press conference. "We agreed there's a need for swift efforts on these fronts." The leaders of the G8 - Britain, Canada, France, Germany, Japan, Italy, Russia and the United States - will be joined by those of some 15 other countries including China, India, Brazil, Australia and eight African states for expanded sessions on global warming and poverty alleviation. German Chancellor Angela Merkel said the G8 leaders would agree on steps to fight the soaring price of food and to guarantee supplies. The steps will provide short-term relief to the crisis and a long-term strategy to increase world agricultural production. Rising food prices have pushed 100 million people below the poverty line, the World Bank estimates, and have sparked street riots around the world. Japanese Press reports have said the G8 will agree to set up a task force on the food crisis or create a system of food reserves much like oil reserves. But aid groups warned that record food and oil prices should not be allowed to derail the leaders' talks on Africa on Monday as the crisis had simply worsened the plight of the poor. On Wednesday, climate change will top the agenda when an expanded group of nations meets. The leaders are expected to pledge to spearhead efforts to halve emissions of greenhouse gases by 2050 after agreeing a year ago to "consider seriously" that goal. Bush pledged to play a "constructive" role on climate change at a summit of rich nations, but hopes for a breakthrough were dim as he pressed developing countries. But he warned that India and China must be part of any long-term agreement, a long-standing sticking point that renewed pessimism that there would be any breakthrough. Japan, the host of the summit, pushed for progress in the fight against global warming but environmentalists said that any agreement was unlikely to be far-reaching. "Yeah, I'll be constructive," Bush told a joint news conference after meeting Japanese Prime Minister Yasuo Fukuda. Fukuda said last-minute climate negotiations were underway within the G8. "The US, I believe, has not really lost a sense of direction. I think that our views are gradually converging," Fukuda said. Last year's G8 summit in Germany agreed, under pressure from Chancellor Angela Merkel, that the major economies would "consider seriously" at least halving greenhouse gas emissions by 2050. South Africa, whose President Thabo Mbeki will take part in Wednesday's meeting, said that last year's agreement at the G8 meeting in Germany "lacked credibility" as it provided no figures for the mid-term until 2020. "Just to say reduction in emissions by 50pc in our view is an empty slogan," said Marthinus van Schalkwyk, the South African environment minister. He proposed that rich nations commit to cut carbon emissions by 25 to 40pc by 2020 - as proposed by the European Union if other major economies come on board. But Japan's Environment Minister Ichiro Kamoshita said the host nation was unlikely to volunteer a specific mid-term target in Toyako. Environmentalists said they expected the issue to be a bargaining chip, with developing countries dangling the possibility of long-term commitments if rich nations step forward on mid-term goals. G8 will be the first for Fukuda, Russian President Dmitry Medvedev, British Prime Minister Gordon Brown and South Korean President Lee Myung-Bak. Major leaders from the developing world, including Chinese President Hu Jintao, Indian Prime Minister Manmohan Singh and South African President Thabo Mbeki, will also attend G8 events. But the atmosphere behind closed doors may get heated.