Updated

Donor nations funding Afghanistan's recovery piled pressure Wednesday on the government to pass election laws seen as crucial to proving the 12-year war and billions of dollars of aid money have not been wasted.

The laws, which will determine how April's presidential election is run, have been delayed for months in parliament, and the international community is increasingly concerned that the poll's credibility is at risk.

"We cannot stress enough the importance of a successful and democratic political transition next year and a credible and timely election," the United States said in a statement at an aid meeting in Kabul.

"We urge the Afghan government and parliament to take the next critical steps and pass electoral legislation that provides for credible appointments of electoral officials and an independent complaints process."

President Hamid Karzai, who has led Afghanistan since 2001, is due to step down after his maximum two terms as president, with a new leader taking over in the country's first-ever democratic transfer of power.

But the last election in 2009 was marred by massive fraud, and the international community fears that another flawed poll would wreck claims that the costly military and aid effort in Afghanistan had been worthwhile.

Donor nations and the Afghan government met on Wednesday in Kabul to assess progress one year after $16 billion of aid was pledged to the country by 2015 at a conference in Tokyo -- on condition of widespread reforms.

After the meeting, a joint-statement declared it was "important for the two elections laws to take effect as soon as they are passed by the parliament".

"The Afghan government and the international community agree that credible and inclusive elections are profoundly important," it added.

Reforms to the Electoral Complaints Commission, which threw out more than one million fraudulent votes in the 2009 election, are a key concern for donors, with some fears that the body could be badly weakened under the new laws.

A corrupt election and a contested result would undermine efforts to establish a functioning state in Afghanistan and could even lead to another era of civil war as the Taliban rebels fight to regain power.

No front-runners have emerged for the election and it remains unclear who will campaign to be the next president.

Among a long list of possible candidates are Qayum Karzai, the president's brother, Omar Daudzai, a former chief of staff, and warlord-turned-governor Atta Mohammad Noor.

"It is of utmost importance that credible, inclusive and transparent elections take place on 5 April next year," Mark Lowcock, the British representative at the meeting, told the meeting.

"We need to see the two election laws pass through parliament before recess on 22 July. If this does not happen it would raise serious questions about the quality and rigour of the elections preparations."

Karzai has repeatedly said that he will leave office in line with the constitution and has vowed to ensure a fair election for his successor.