WASHINGTON (AFP) - Britain's Amir Khan will defend his world light-welterweight titles against US mandatory challenger Lamont Peterson on December 10 in Washington, according to promoter Richard Schaefer. Golden Boy Promotions' Schaefer told ESPN on Thursday that Khan will fight at a venue to be determined in the US capital, where Peterson is a hometown hero but where Khan visited this month for a dinner honoring Muslim athletes. Khan, 26-1 with 18 knockouts, has won eight fights in a row, most recently last July in Las Vegas when he knocked out Zab Judah in the fifth round to unify the World Boxing Association and International Boxing Federation titles. Peterson, 29-1-1 with 15 knockouts, fought Victor Ortiz to a 10-round draw last December on the undercard of Khan's unanimous decision victory over Marcos Maidana.