LONDON — Allied countries are pledging to send more help to Afghanistan before a much anticipated decision from President Barack Obama on whether to send more troops, NATO's secretary-general said Thursday.

Anders Fogh Rasmussen also agreed with British Prime Minister Gordon Brown handing over parts of the volatile Helmand province could start as early as June, but he said more resources and help from the Afghan government was needed.

"We need to train and educate Afghan soldiers and police with the aim to hand over responsibility to the Afghans themselves — province by province as capacity develops," Rasmussen said. "This is the reason why we need more resources for our training mission. Right now, the Afghan security forces do not have the capacity."

Britain has offered to add 500 more troops to its 9,000 contingent if the Afghan government cleans up corruption and other allied countries provide resources. Turkey has already boosted troops but in a humanitarian capacity, not combat.

Waning public support for the mission that began after the Sept. 11, 2001, attacks has kept other allied nations from publicly committing to more troops, but Rasmussen said private pledges were being made.

"We have already received quite a number of pledges, and I would also encourage allies to follow suit and welcome the British decision to add troops," he said. "Based on this principle of solidarity, I think all allies will follow suit — one way or the other."

It was unclear how many countries had made commitments or whether those pledges would be in the form of troops or training personnel.

NATO commanders in Afghanistan have called for an additional 30,000 troops, but Rasmussen said numbers had not been finalized.

He said allied countries understood the importance of the mission.

"I think that all governments realize that we are in Afghanistan to prevent the country from once again becoming a safe haven for terrorists. If we leave Afghanistan behind, terrorism would easily spread from Afghanistan through Central Asia and further to destabilize Pakistan — a nuclear power — and that would be a very dangerous situation."

He also acknowledged problems with the Afghan government.