Afghan President Hamid Karzai must face an election run-off against his main rival on Nov. 7, officials said Tuesday, to resolve a disputed first round that plunged the country into months of political uncertainty. Karzai welcomed the ruling by the government-appointed Independent Election Commission (IEC) after hours of closed-door meetings with western diplomats and mounting international pressure to accept the need for a second round. The heavily disputed Aug. 20 vote has fanned tension between Karzai and the West and complicated U.S. President Barack Obama's decision on whether to send thousands more U.S. troops to Afghanistan to fight a resurgent Taleban. With US Senator John Kerry by his side, Karzai told reporters at a news conference in Kabul that he accepted the IEC's ruling that a run-off must be held against his former foreign minister Abdullah Abdullah. “We believe that this decision of the IEC is legitimate, legal and constitutional and that it strengthens the path towards democracy,” Karzai said. The IEC's ruling came after a UN election fraud watchdog invalidated tens of thousands of votes for Karzai. That investigation, published Monday, pushed the vote for Karzai back below the 50 percent level needed to avoid a run-off. The decision however presents a logistical nightmare, with Afghanistan's harsh winter approaching fast. In an apparent show of solidarity, Karzai was also flanked by the United Nations' top representative in Kabul, Kai Eide, and the US and British ambassadors. Kerry said that Abdullah had also agreed with the second-round verdict. He said there had been no discussion of a national unity government, suggested by some analysts as another way out of the impasse. Abdullah Abdullah has agreed to participate in a second-round vote, his spokesman said Tuesday. “Both Dr Abdullah and (president) Hamid Karzai have insisted a second-round election take place in 14 days,” Sayed Fazil Aqa Sancharki said.