Reporting from Kabul, Afghanistan, and Washington-- President Obama, facing an unanticipated setback to his goals in Afghanistan as he weighs whether to send in more troops, warned the country's leader Monday to get serious about eradicating corruption and developing a stable government.

Obama's administration faces a more difficult job in achieving his objectives after Afghan election officials canceled a runoff vote that had been scheduled for this weekend and declared President Hamid Karzai the winner of a new five-year term. The move, which follows August's fraud-tainted election, came after former Foreign Minister Abdullah Abdullah bowed out of the rematch Sunday, saying the government-appointed electoral commission was biased in favor of Karzai.

The outcome left a shadow over Karzai and roused antiwar voices in Washington. Though administration officials called the end to the election uncertainty a step forward for Afghanistan, Obama could be harder-pressed to justify the major U.S. troop increase that his military leaders have recommended to bolster the fight against Islamic militants.

The president will decide in coming weeks on the request for a reported 40,000 additional troops, which would make for a U.S.