KABUL, AFGHANISTAN (AP) - Afghanistan's President has won a second term in office, securing a tiny majority of the ballots cast three months ago, according to a preliminary vote count announced on Sunday (Dec 22).

His opponents can still challenge those results. If the results hold and Mr Ashraf Ghani remains president, it could give him the authority he has been seeking to demand a leading role in peace talks with the Taleban.

The country's election commission said Mr Ghani got 50.64 per cent of the votes in the Sept 28 presidential poll.

The results of the presidential election have been repeatedly delayed amid accusations of misconduct and technical problems.

Mr Ghani appears to have beaten out his main challenger Abdullah Abdullah, who serves as the country's chief executive in a fragile national unity government and who rejected the results.

Mr Ghani and his government have been sidelined during the past year of direct talks between the US and the Taleban.

Washington seeks to withdraw its combat troops and end 18 years of fighting in Afghanistan, America's longest war.

In a live TV speech on Sunday, Mr Ghani hailed the announcement as a victory of the nation and pledged to "represent the whole nation".

"We will connect and unite all Afghans. We will end the crisis and all divisions by building a responsible government," he told a crowd of supporters gathered at the presidential palace.

As for foreign aid, "We are not asking for a donation, our shared interests ensure our relations with countries," he said.

Mr Abdullah's office released a statement saying the results were "not legitimate" and that they were "based on the fraudulent vote without considering the legal demands of the candidates".

US Ambassador to Afghanistan John Bass tweeted: "It's important for all Afghans to remember these results are preliminary. Many steps remain before final election results are certified, to ensure the Afghan people have confidence in the results."

In November, the election commission tried to launch a ballot recount, but Mr Abdullah halted the attempt, saying he would not let his observers participate.

He eventually allowed a recount to go forward earlier this month.

Thousands of Mr Abdullah's supporters had rallied in November against what they said was the presence of faked ballots.

The controversial recount seemed set to favour Mr Ghani.

Ms Hawa Alam Nuristani, the head of the Independent Election Commission, announced the preliminary results at a press conference in Kabul.

She did not specify when the final results, long overdue, would be announced.

For now, Mr Ghani's lead appears secure as there also won't be any decision on whether a second round of voting is needed until the final results are out.

Afghan election laws say a runoff must take place if no candidate obtains over 50 per cent of the votes.

The preliminary results found Mr Ghani won 923,868 votes, while Mr Abdullah won 720,990 votes, according to Ms Nuristani.

She did not give a specific percentage for Mr Abdullah during the press conference in the capital, Kabul, but he appeared to have received 39.52 per cent.

The UN secretary-general's special representative for Afghanistan, Mr Tadamichi Yamamoto, said the commission "has an obligation to adjudicate any complaints it receives transparently and thoroughly so the election process may conclude in a credible manner" and that "all candidates have the chance to raise any concerns they may have".

The 2014 presidential election was mired in accusations of widespread fraud.

That led the US to cobble together a unity government between Mr Ghani and Mr Abdullah, the two leading contenders, but their partnership has been fraught with bickering and rifts.

There was no immediate comment from the Taleban, who refuse to negotiate with the Kabul government.

Mr Ghani has been demanding a ceasefire before engaging in talks, something the Taleban have steadfastly refused.

The Taleban currently control or hold sway over half the country and stage near-daily attacks targeting Afghan forces and officials or those seen as allied with the government - but also killing scores of civilians in the process.