The seven most industrialized countries have agreed to grant 100 percent debt relief for the world's poorest nations -- most of them in sub-Saharan Africa. The agreement came Sunday at the end of a two-day meeting of the Group of Seven (G-7) in London. The group said details of the offer must be negotiated with the International Monetary Fund, the World Bank and the African Development Bank. The 27 countries classified as the world's poorest owe 70 billion dollars to the international lending institutions. Britain, for its part, says it will spend 50 million dollars this year to give immediate debt relief to 19 developing nations. The British plan targets Armenia, Benin, Bolivia, Burkina Faso, Ethiopia, Ghana, Guyana, Mali, Madagascar, Mauritania, Mongolia, Mozambique, Nicaragua, Niger, Senegal, Sri Lanka, Tanzania, Uganda and Vietnam.