German Chancellor Angela Merkel and US President Barack Obama will discuss the role of developing countries in the International Monetary Fund in talks next week, a source in Berlin said on Friday. The senior German official, who spoke on condition of anonymity, said Merkel and Obama would talk in Washington about \"whether it is set in stone that an American is always head of the World Bank and a European at the IMF\". They will discuss \"how we deal with developing nations\" within the IMF in future, the official said. Germany strongly supports French Finance Minister Christine Lagarde for the IMF post vacated last month by Dominique Strauss-Kahn after the Frenchman was arrested and charged with sexual assault in New York. And last week US Secretary of State Hillary Clinton said she \"personally\" welcomed Lagarde\'s candidacy for the IMF leadership, although she noted the United States had not taken an official position. But Mexican central banker Agustin Carstens has thrown his hat in the ring, saying becoming the next IMF chief would be a major victory for the entire developing world. Carstens, 52, has decried what he called a lack of European \"credibility\" in seeking one of their own to replace Strauss-Kahn as the head of the world finance body. Merkel said this week on a visit to Singapore that Lagarde was well qualified to head the IMF, urging emerging countries to give her an \"objective\" assessment. The German leader will visit Washington from Monday to Wednesday with five members of her cabinet and accept from Obama the Presidential Medal of Freedom, the highest US honour for civilians.