Afghan President Hamid Karzai responded to international criticism of corruption in his administration by calling Tuesday for large-scale reform to stamp out the bribery and graft that permeate ministries and state offices. Karzai has been under pressure to clean up his government following this year's fraud-tainted election. "I know corruption exists in the government and elsewhere. Let's be realistic. Let's acknowledge the problem first," Karzai said at the opening of a three-day conference on corruption that he ordered in his first decree after retaking office last month.