Afghanistan's presidential election will be held on April 5, 2014, months ahead of the final withdrawal of NATO combat troops from the insurgency-plagued nation, a poll official said on Tuesday. President Hamid Karzai, who is serving his second term, is constitutionally barred from running in the election and has been under pressure from opposition groups to announce the date. Afghanistan's Independent Election Commission said in a statement that the date for the vote was set and would be officially announced at a press conference on Wednesday. But a senior official in the commission told AFP on condition of anonymity that the scheduled date was "Hamal 16, 1393", referring to the Afghan solar calendar. The date coincides with April 5, 2014. Karzai's re-election in 2009 was marred by widespread allegations of fraud, and the credibility of the next vote is seen as crucial to Afghanistan's stability after the NATO withdrawal. "The transparency and credibility of the elections are of paramount importance for NATO," its spokesman in Afghanistan, Dominic Medley, said last week. The International Crisis Group think-tank warned this month that the Kabul government could fall apart after NATO troops withdraw, particularly if the presidential elections are plagued by fraud. The Afghan government announced last week that it will not accept foreigners on a key election watchdog for the presidential elections, a move that may undermine the credibility of the poll. Karzai said the presence of foreigners in the Electoral Complaints Commission went against the "sovereignty of Afghanistan", suggesting that the two foreigners on the five-member body will be removed. Karzai's spokesman, Aimal Faizi, said foreigners were still welcome as election monitors but the government was able to ensure the poll was fair. Karzai has been the only elected head of state in Afghanistan since a 2001 US-led invasion brought down the hardline Islamist Taliban regime.