Afghanistan: US says may pull out all troops as Afghan leader holds up deal --- WASHINGTON — Afghanistan's President Hamid Karzai has refused to sign a security deal with the United States, the White House said, and Washington may have to resort to the "zero option" of withdrawing all American troops from the strife-torn country next year, as it did in Iraq. -- Karzai told U.S. National Security Advisor Susan Rice in Kabul on Monday that the United States must put an immediate end to military raids on Afghan homes and demonstrate its commitment to peace talks before he would sign a bilateral security pact, Karzai's spokesman said. -- The White House said Karzai had outlined new conditions in the meeting with Rice and "indicated he is not prepared to sign the (bilateral security agreement) promptly." -- Rice, who made a three-day visit to Afghanistan to visit U.S. troops, told Karzai it was "not viable" to defer signing the deal until after the election, the White House said. -- "It is vitally important that there is no more killing of Afghan civilians by U.S. forces and Afghans want to see this practically," Faizi said. -- Karzai also called on Washington to send remaining Afghan detainees at the U.S. military detention center in Guantanamo Bay, Cuba, back to Afghanistan, saying that the Loya Jirga, the assembly of elders and leaders that convened last week to debate the deal, had endorsed the pact with this condition. -- Faizi said Karzai also asked the U.S. officials to guarantee that the United States would refrain from endorsing any candidate in national elections next year. -- Faizi said the Afghan president had asked his American visitors to return to the U.S. president with his message. -- "The ball is in your court now, and get back to us," he said.