Afghanistan's elections, already postponed until September, will still be jeopardized unless security improves and military forces are disarmed, a senior U.N. official warned Tuesday.

Undersecretary-General for Peacekeeping Jean-Marie Guehenno (search) said it is vital that the Afghan government meet its commitment to speed up disarmament efforts, demobilize 40 percent of current militias and lock up all heavy weapons by June.

He also stressed that increased international security assistance is essential to protect the electoral process "both from factional threats or more radical attempts to oppose the process."

The elections had originally been set for June but President Hamid Karzai (search) delayed them late last month until September. He was heeding U.N. warnings that neither security nor logistics were in place for a quicker vote.

"Afghan and international security forces currently available are limited, and will be overstretched if they have to face the task of holding meaningful and credible elections across the country," Guehenno warned. "Without improvements in the security situation, the elections will be threatened."

Guehenno spoke at an open Security Council meeting where speakers welcomed the $8.2 billion pledged for Afghanistan's reconstruction at last week's conference in Berlin and called for improved security ahead of the elections.

The council adopted a statement that stressed "the importance of a secure environment for free, fair and credible democratic elections" and called for stepped up efforts by the Afghan government and the international community to achieve a successful ballot.

The council also acknowledged NATO's plans to expand the alliance's peacekeeping mission beyond Kabul. The alliance wants to have teams of several hundred soldiers in five northern cities by late June, but has been struggling to muster the troops to do the job.

U.S. deputy ambassador James Cunningham told the council that the United States has established nine of the 12 provincial military teams currently operating in Afghanistan.

He called for additional teams, saying they are "increasingly popular, not only with the leadership of the transitional administration, but also with the Afghan citizens, to whom these teams provide much needed security and reconstruction."

Guehenno expressed hope that the new Afghan army will be able to deter factional violence and newly trained interior ministry units might be deployed in larger numbers to create a freer environment for the elections.