Bowing to intense international pressure, Afghan President Hamid Karzai agreed Tuesday to a runoff next month with his main challenger in August's disputed presidential election. 'This is for the good of our country,' the Afghan leader, looking pale but composed, told a packed news conference at his presidential palace. The announcement of a Nov. 7 runoff contest came 24 hours after a U.N.-backed panel investigating charges of fraud in the August balloting invalidated nearly a million votes cast for Karzai, stripping him what his camp had declared was a solid first-round victory. Karzai now faces a contest with Abdullah Abdullah, his former foreign minister. The president is considered likely to emerge the ultimate victor; the fraud-adjusted vote tally still gave him 48 percent to Abdullah's 31 percent, with the rest of the count split between a crowded field of other challengers. Western military forces and Afghan and international election officials will have to scramble to stage the logistically complex repeat election. The original vote was marred by massive fraud and shadowed by the threat of insurgent violence -- though there were no major election-day attacks -- and those same concerns will arise in the runoff. Military commanders quickly expressed confidence they could provide the necessary security, and Western officials said even with winter fast closing in, the new balloting could go ahead as scheduled. At his news conference at the presidential palace, Karzai was accompanied by Sen. John Kerry, D-Mass., chairman of the Foreign Relations Committee, and Kai Eide, the Norwegian who heads the U.N. mission in Afghanistan. A number of Western ambassadors were also present in a show of support for the runoff and the diplomatic resolution of what had been a tense confrontation. Kerry, who had spent recent days closeted in talks with the Afghan leader, praised Karzai as a 'statesman' for accepting the revised tally and agreeing to the runoff. Karzai's capitulation averted what could have been a severe constitutional crisis. Afghan law calls for a runoff to be held if no candidate receives more than 50 percent of the vote, but Karzai's aides for weeks had been harshly critical of the recount process and had hinted he might try to quash a runoff. The relief on the part of the international community was palpable. The election squabble has already delayed key decisions by NATO and the Obama administration over troop increases and war strategy. 'In a country which is a young democracy, it is of particular importance that the institutions that underpin democracy work,' said Eide, the U.N. mission chief. 