Ashraf Ghani, one of two candidates disputing the Afghan presidential election, has called for an "extensive audit" of votes.

He made the appeal before meeting US Secretary of State John Kerry, who arrived in Kabul to try to resolve a growing political crisis.

Mr Kerry is also meeting Mr Ghani's rival Abdullah Abdullah.

Mr Ghani came out ahead in preliminary results from the second round, but both candidates allege fraud.

The audit would help ensure the "integrity and the legitimacy that the people of Afghanistan and the world will believe in," Mr Ghani said.

The announcement was welcomed by Mr Kerry, who arrived in Afghanistan on Friday in a hastily arranged visit.

"No one is declaring victory at this time. The results have yet to be finalised and so those questions have to be resolved and I'm very appreciative that Dr Ghani respects that" he said.

Current President Hamid Karzai, who took power after the US-led overthrow of the Taliban, is stepping down after more than 10 years.

Secretary of State John Kerry's visit is "critical" in ensuring the election authorities deliver a credible result which is "broadly acceptable" to the Afghan people.

In mathematical terms that means pushing for a much broader audit of votes - beyond the 3 million currently identified. In diplomatic terms it means finding a way through the fog of mistrust so that both sides start working together.

When earlier this week Abdullah Abdullah faced pressure from his supporters to declare a parallel government, the US quickly responded by warning that such an act would trigger the suspension of aid and security assistance.

Mr Abdullah pulled back from the brink but he will have to show his frustrated followers that the meeting with John Kerry has broadened the scope of the audit to prevent them spilling onto the streets - angry and armed.

Ashraf Ghani will be looking for some lines in the sand. One of his close aides told me they would continue to co-operate with the election authorities but feared that the "cascading demands" of Abdullah's side - was simply a "delaying tactic. They're looking to John Kerry to manage that.

(BBC)