Afghan President Hamid Karzai pledged Thursday that he would step down as required by the constitution at the end of his second term in 2014 and that nothing would prevent presidential elections being held.

The election coincides with the scheduled withdrawal of NATO forces from Afghanistan and questions have been raised about whether the security situation could make it impossible for the vote to go ahead.

But the Western-backed Karzai, who has been the only elected head of state in Afghanistan since the 2001 US-led invasion brought down the Taliban, said no security reasons would prevent the elections."Even if my term is prolonged by one day it will be illegitimate," he told a news conference.

"The election will definitely happen, 100 percent will happen, on due time. You can choose your favorite candidate. Whoever you like, vote for him."Karzai's re-election in 2009 was accompanied by widespread fraud. The international community sees the next vote as one of the last major hurdles before NATO combat troops withdraw at the end of 2014.

Later dropping the idea,Karzai suggested in April that he was considering calling an early election to leave  time for the new government to handle a  transition from US forces to Afghans.