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 US said in a statement at an aid meeting in Kabul.
The head of the UN mission in Afghanistan, Jan Kubis, said that "any further delay seriously risks jeopardising" preparations for the presidential election, which is scheduled for April 5.
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.
More From This Section
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 has been worthwhile.
Reforms to the Electoral Complaints Commission, which threw out one million fraudulent votes in the 2009 poll, are a key concern for donors, with some fearing parliament may approve legislation that actually weakens the watchdog.
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.