"The Afghan government is totally ready for the inauguration ceremony of the new president on the date of September 2," the presidential palace said in a statement yesterday.
The date would not change, according to the statement, which was issued following talks between Karzai and the head of the UN mission in Afghanistan Jan Kubis.
The new president was due to be inaugurated on August 2, in Afghanistan's first democratic transfer of power, but the government has been paralysed for months after the first round of the presidential election failed to produce a clear winner and the second round of voting in June triggered allegations of massive fraud.
As fears grew of a return to civil war, the United States last month brokered an emergency deal designed to end the impasse between poll rivals Ashraf Ghani, a former World Bank economist, and former anti-Taliban fighter Abdullah Abdullah.
But neither candidate appears willing to back down, and the dispute looks set to break out again in the coming days when early results emerge from an anti-fraud audit of all eight million votes.
The audit has checked more than 60 per cent of votes, and the next stage of invalidating fraudulent ballots will likely raise tensions between the candidates - who are also meant to be in talks about a post-election unity government.
The United States had been pushing for the next president to be inaugurated before a NATO summit starting on September 4, which should sign off on follow-up support after the transatlantic alliance's combat mission in Afghanistan ends this year.
The political crisis would worsen sharply if either candidate pulls out of the audit or rejects its outcome, with possible angry street protests in Kabul by aggrieved supporters set to pose a major challenge to the national security forces.
The election deadlock has revived ethnic divisions that lay behind the 1990s civil war in Afghanistan.