TOKYO (AFP) - Japan's Finance Minister quit Tuesday after triggering a political storm over his apparently drunken behaviour at a meeting of world powers on the global economic crisis. Shoichi Nakagawa, a close ally of unpopular Prime Minister Taro Aso, was incoherent and slurred his speech at a news conference on Saturday after the Group of Seven talks in Rome, prompting calls for his sacking. "I caused a lot of trouble due to my drinking. Considering my condition, I'm not in a mood to drink alcohol right now. There are many things I have to reflect on," Nakagawa told reporters after stepping down. Economics Minister Kaoru Yosano, a free-market advocate, will take the additional post. Nakagawa said earlier he had sipped some wine with lunch before the G7 Press conference but blamed jet lag and cold medicine for his drowsiness. The 55-year-old political heavyweight said he would voluntarily check into hospital to rest after being diagnosed with a cold and fatigue. The debacle could hardly have come at a worse time for Aso, whose popularity had already slumped below 10 per cent according to one poll, battered by concerns over his handling of the economy and repeated gaffes. "The cabinet's remaining days are numbered. The focus has shifted to who will succeed Aso," he said. The uproar overshadowed a visit by US Secretary of State Hillary Clinton, who announced that President Barack Obama would receive Aso in Washington next week before any other foreign leader - rare good news for Japan's premier.