The United Nations says that more NATO troops are needed in Afghanistan by the end of next month, to ensure security for national elections in September. U.N. Special Representative to Afghanistan Jean Arnault says that there is public willingness and determination to take part in the country's first free polls in decades.

He told reporters in the capital, Kabul, that the process of voter registration is proceeding well as more and more Afghans are signing up for the vote.

But Mr. Arnault says a recent wave of violence, including deadly attacks on local and foreign aid workers, shows the security situation across Afghanistan is becoming more volatile.

"The events of the past three weeks have demonstrated that security is not improving," he said. "If anything it has become more volatile."

Mr. Arnault says that more NATO troops will be needed by the end of next month along with a surge in disarmament of private Afghan militias once nomination of candidates and campaigning starts.

"All these requirements prod us to turn again to the international community and say: 'The time is now,'" said Mr. Arnault.

A growing armed insurgency led by supporters of the ousted Taleban government coupled with power struggles among regional warlords have raised doubts about holding of a free and fair election in Afghanistan.

NATO is leading an international force of nearly 6,500 peacekeepers confined mainly to Kabul. It has promised to expand the force, but member states have been reluctant to provide more troops.

Mr. Arnault urged NATO members to make a final decision to send more troops when they hold a summit meeting later this month in Istanbul.

The top U.N. representative in Kabul also says that a target of disarming, demobilizing, and re-integrating 40 percent of militiamen across Afghanistan by the end of this month is far from being met. He urged Afghan warlords to cooperate with U.N.-backed efforts to disarm their private armies.