Afghan President Hamid Karzai Monday told a major conference on the future of his country after NATO combat troops withdraw in 2014 that it would need international help for at least another decade.

Karzai told around 1,000 delegates gathered in the western German city of Bonn for the one-day meeting that his government would battle corruption and work toward national reconciliation but it needed firm international backing.

"We will need your steadfast support for at least another decade" after the troops' pullout, he said.

The meeting comes 10 years after another conference here put an interim Afghan government under Karzai in place after US-led troops ousted the Taliban in the wake of the September 11 attacks.

However, Pakistan and the Taliban -- both seen as pivotal to any end to the bloody strife in Afghanistan a decade on -- have bowed out of Bonn, dampening already modest hopes for real progress.

There are around 140,000 international troops in Afghanistan and all NATO-led combat forces are due to leave by the end of 2014, when Kabul will assume responsibility for the country's security.

The event's host, German Foreign Minister Guido Westerwelle, insisted there would be no rush to the exit.

"We send a clear message to the people of Afghanistan: we will not leave you alone, you will not be abandoned," he said.

"Afghanistan and its people need a clear and reliable commitment to a long-term engagement for the next decade beyond 2014."

US Secretary of State Hillary Clinton told a meeting of representatives of civil society including women's groups that Western countries had also come to Bonn to hear about the most pressing needs on the ground.

"We need your best advice about how we can help the government develop ...professionalism and abilities." Clinton added: "We have a duty to our taxpayers to make sure money is well spent. The corruption problem is a real one."

Rage over an air strike late last month by NATO troops stationed in Afghanistan that killed 24 Pakistani soldiers led Islamabad to snub the gathering.

US President Barack Obama called Pakistan's President Asif Ali Zardari Sunday to express his regrets over the "tragic loss", saying the casualties were not intentional, but Islamabad remained unmoved.

Clinton has voiced regret over the boycott because she said Pakistan has a stake in a secure and stable Afghanistan but aides travelling with her denied Pakistan's absence would undermine the conference.

"I don't think it will impact the conclusions of the conference in any way," a senior State Department official told reporters on condition of anonymity.

Germany calls Pakistan's pull-out a "setback" for the meticulously planned conference. But organisers say they are confident Islamabad will also see itself as committed to the principles laid out in the meeting's final declarations.

The Taliban, leaders of the country's brutal, decade-long insurgency, have also stayed away, saying the meeting will "further ensnare Afghanistan into the flames of occupation".

National reconciliation, along with the transition to Afghan sovereignty and international engagement after 2014, had originally topped the conference's agenda.

But such hopes soured after tentative contacts collapsed and the September assassination of Karzai's peace envoy, former president Burhanuddin Rabbani, which was blamed on the Taliban, derailed any prospects of progress.

Officials from the primary delegations spent much of the weekend thrashing out the conference's written conclusions, which are expected to map out "mutual credible commitments" by Afghanistan and the international community after 2014.

Sources said they would neither include specific aid nor troop pledges but rather outline what role the country's allies can play as it seeks to steer towards stability.

Diplomats say Western countries will in particular seek to allay Kabul's fears that a looming global recession will distract them from the enormous challenges facing the strife-wracked nation.

Suicide bombings, improvised explosive devices and other attacks already kill hundreds of civilians every year, and many Afghans worry that security will worsen after 2014, or even that civil war could reignite.

Meanwhile, citing German intelligence documents, daily Bild reported that Karzai was seeking constitutional changes to remain in power after his second and by law final term ends in 2014. AGENCIES