KABUL (AP) – President Hamid Karzai was effectively handed a second five-year term Sunday when his only challenger dropped out of the race, and the Obama administration said it was prepared to work with the man it has previously criticized to combat corruption and confront the Taliban insurgency.

President Barack Obama has been waiting for a new government in Kabul to announce whether he will send tens of thousands of new troops to Afghanistan. The war has intensified and October was the deadliest month of the eight-year war for U.S. forces.

Former Foreign Minister Abdullah Abdullah announced his decision to quit six days before the runoff election, after last-minute talks led by the U.S. and United Nations failed to produce a power-sharing agreement acceptable to Karzai, according to a Western diplomat who spoke on condition of anonymity because of the sensitivity of the negotiations.

In an emotional speech, Abdullah told supporters that he could not accept an runoff led by the same Karzai-appointed election commission that managed the fraud-marred vote in August. The runoff was set for Nov. 7 after U.N.-backed auditors annulled nearly a third of Karzai’s votes as fakes.