Donor countries have pledged $8.2bn (£4.4bn) in aid for Afghanistan over the next three years, said Afghan Finance Minister Ashraf Ghani. The pledges were made after an appeal by Afghan President Hamid Karzai at a two-day donors conference in Berlin. Afghanistan has also agreed with its six neighbouring countries to step up cooperation over drug trafficking. President Karzai told delegates that drugs were undermining the \"very existence\" of his country. Mr Ghani said he was \"delighted\" by the pledges from donor countries - which are significantly higher than at the last donors conference in Tokyo in 2002. The largest donor is again the United States, which has promised $2.2bn over the next two years. Britain has virtually doubled its financial commitment, by pledging $900m (£500m). \"The pledges today make it possible to meet the hopes of our citizens that we will be able to participate in a dream of a better future,\" Mr Ghani told a press conference. He said that $4.4bn had been pledged for this year alone. \"This is 100% of our target\". But the figure still falls far short of what the Afghanis had hoped for. The Kabul government says it needs $27.5bn over seven years to rebuild the country. Officials hope more money may be forthcoming if elections planned for September are successful, adds our correspondent. The World Bank\'s country director for Afghanistan, Alastair McKechnie, has defended the amount of development aid being sought by Kabul. He put the total cost of two decades of war at about $240bn. \"The figure of $27.5bn may seem a lot but it will simply help Afghanistan get back on the track from which its people were brutally wrenched in the late seventies,\" he said. (BBC)