A spokesman for the Afghan election commission said that it is too late for Abdullah to officially withdraw and that a boycott will not prevent the runoff from going forward.
“The election will be held and all procedures will go as normal,” Noor Mohammad Noor said.
U.S. officials have been concerned that the second round would expose Afghan civilians to attack by Taliban militants opposed to the election.
Last Wednesday, Taliban attackers killed five U.N. employees — including one American — and three Afghans in a brazen assault on a residential hotel housing international staff in the heart of Kabul. The three attackers also died.
Afghan intelligence chief Amrullah Saleh said Afghan authorities had advance information that a Taliban attack in Kabul was in the works but was expected it during rush hour, and officials were unsure of the target.
Instead, the attackers struck just before dawn. Saleh said eight people had been arrested for their roles in the attack, including an Afghan imam who was apprehended when he arrived by plane in Jiddah, Saudi Arabia.
Saleh said the detainees told interrogators the attackers came from Pakistan’s Swat Valley and that the al-Qaida mastermind fled across the border into Pakistan’s lawless tribal area, where the al-Qaida leadership is believed hiding.
Casualties have been on the rise since President Barack Obama sent more troops to confront the Taliban.
On Saturday, the NATO-led force announced the latest coalition death in the war. The Canadian Defense Department said the casualty was a 24-year-old Canadian national killed in a bomb blast outside the southern city of Kandahar on Friday.