More Nato troops will be needed in Afghanistan by the end of July along with a surge in disarmament of factional militias if security is to be sufficient for elections in September, the United Nations said on Monday.
UN Special Representative to Afghanistan Jean Arnault said that a decision would have to be taken by the end of this month whether polls can be held as scheduled.
He said there would be intense discussions on whether security requirements could be met and international donors would also need to provide tens of millions of dollars of funds that had been pledged, but not yet delivered.
Afghans had demonstrated their enthusiasm by registering at a rate of more than 100,000 a day to vote in what are billed as the country's first free polls, Arnault told a news briefing.
"That very determination places an obligation on many other actors inside Afghanistan and outside Afghanistan," he said.
Attacks in recent weeks on foreign aid and reconstruction workers and UN offices showed the security situation was becoming more volatile and more troops would be needed once nomination of candidates and campaigning started, he said.
"All the requirements prod us to turn again to the international community and say: 'The time is now'."
He called on Nato members at a summit in Istanbul on June 28 and 29 to make a final decision to send more troops and added that if elections were to be held at the end of September, "You would need these troops to be available by the end of July."
Nato has said it will expand its force of about 6,400 peacekeepers now confined mainly to Kabul. But even as Islamic militants who have vowed to disrupt the polls step up attacks, member states have been reluctant to provide more troops.