Kabul ? U.N.-backed fraud investigators on Monday threw out nearly a third of President Hamid Karzai’s votes from the August election, undercutting his claim of victory and stepping up the pressure for him to accept a runoff.

President Barack Obama’s administration has been holding off on a decision to send more troops to Afghanistan until a credible government is installed in Kabul.

Both U.S. Secretary of State Hillary Rodham Clinton and U.N. Secretary-General Ban Ki-moon signaled on Monday that a resolution was near.

Clinton said Karzai planned to announce his intentions today, adding that she was “encouraged at the direction the situation is moving.”

A spokeswoman for Ban said he spoke with Karzai and the Afghan leader assured him he will “fully respect” the constitutional process even if it means a runoff against his top challenger, former Foreign Minister Abdullah Abdullah.

The findings by the Electoral Complaints Commission dropped Karzai’s votes to 48 percent of the total, below the 50 percent threshold needed for him to avoid a runoff, according to calculations by independent election monitors.

Still, it was uncertain whether the Afghan-led Independent Election Commission, which is dominated by Karzai supporters, would accept the findings and announce a second round.

Karzai campaign spokesman Waheed Omar said the Karzai camp was waiting for the election commission to formally certify the U.N.-backed panel’s findings, thereby giving them the force of law. Although short of an unequivocal pledge to accept a run-off, the statement appeared to represent a step in that direction after days of outright rejection.

Last week Karzai aides suggested he might contest the findings, setting off a series of last-minute diplomatic efforts, including visits by U.S. Sen. John Kerry.

Karzai met again late Monday with Kerry and U.S. Ambassador Karl Eikenberry to discuss the standoff.

The two-month election crisis threatens to undermine the Obama administration’s Afghan strategy at a time when public support for the eight-year war is declining in the U.S. and the Taliban-led insurgents are gaining strength. The White House says Obama will not decide whether to send thousands more U.S. troops to Afghanistan until the political crisis is resolved.

However, U.S. Pentagon chief Robert Gates told reporters Monday that Obama may not be able to wait until the disputed Afghanistan elections are resolved to decide on a new war strategy.