Media playback is unsupported on your device Media caption President Karzai: "Our young democracy remains fragile"

Afghan President Hamid Karzai has said international support after foreign forces withdraw in 2014 is crucial if Afghanistan is to remain stable.

His comments opened a major global conference on Afghanistan's future in the German city of Bonn.

It comes 10 years after a similar gathering held in the city, weeks after the Taliban fell from power.

But key player Pakistan is boycotting this round in protest at a Nato attack on a border checkpoint last month.

Nato apologised for the air strike on 26 November in which 24 Pakistani troops were killed and on Sunday US President Barack Obama also offered his condolences, but Pakistan has insisted that it will not reverse its decision on the talks.

President Karzai hailed the progress Afghanistan had made in the decade since the last conference but warned that such gains were by no means secure. He said the conference presented an opportunity for Afghanistan to consolidate its gains.

"The people of Afghanistan are looking to this conference for clear affirmation of commitment to make security transition and economic progress irreversible," he said.

He added that the country does not want to be a burden on the international community for a day longer than necessary, but said that support would be needed for at least another decade.

Analysis Kabul and the international community may be playing down the absence of Pakistan, but the truth is more complex. Kabul had been hoping that Bonn would be where the international community pressured Pakistan to allow peace talks with Taliban leaders. It also wanted leaders to ask for guarantees that Pakistan would stop ''interfering in Afghanistan's internal matter'' as one senior Afghan aide put it. That is now not possible. There are other stakeholders here too. For example, Afghan women's groups want international guarantees and backing to consolidate gains made for women. But analysts warn that Afghanistan's road to peace is paved with peril and it can only be achieved if the international community commits to a long-term policy for Afghanistan. Afghans wary as Bonn talks open Afghan peace at stake in Bonn

As the conference got under way the US and other nations vowed to continue supporting Afghanistan's fragile recovery after 2014.

The US "intends to stay the course with our friends in Afghanistan", Secretary of State Hillary Clinton told the summit.

Speaking later, she said she thought it "unfortunate" that Pakistan was not attending the talks.

"We regret the choice that they made because today's conference was an important milestone toward the kind of security and stability that is important for Pakistan as well as for Afghanistan," she told reporters on the sidelines of the conference.

"We continue to believe that Pakistan has a crucial role to play."

Mrs Clinton is one of about 1,000 delegates from 100 countries and international organisations taking part in Monday's gathering.

President Karzai also made pointed reference to what he called the "problem of sanctuaries [for terrorists] outside Afghanistan," which he said remained unaddressed and posed a threat to the security of the wider region and the world.

Media playback is unsupported on your device Media caption Hillary Clinton commented on Pakistan's absence from the talks

Analysts say that Pakistan is crucial if any progress is to be made on negotiating a long-term peace with the Taliban - a goal that President Karzai said he remained committed to.

Afghan and US officials have repeatedly said that militant groups operating in Afghanistan are based in Pakistan - a charge Pakistan denies.

Key issues on the conference agenda include reconciliation with the Taliban and the cost of rebuilding Afghanistan beyond 2014.

Estimates say about £4.5bn a year is needed by 2020 if the country is to stay at current levels of development.

More than 500 Nato troops have been killed so far this year in Afghanistan. Much of the worst fighting takes place in the east, near the Pakistani border.

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Taliban talks

Efforts to launch talks with the Taliban have brought no tangible result so far.

In September militants assassinated former President Burhanuddin Rabbani, who was leading Kabul's effort to broker peace with the insurgents.

"Right now we don't know their address. We don't have a door to knock on," Afghanistan's ambassador to the US, Eklil Hakimi, told AP news agency.

The US and other Western nations have long suspected Pakistan of harbouring the Taliban and other insurgent groups, including the Haqqani network, blamed for attacks on the Afghan side of the border.

Correspondents say that a failure to bring the Taliban into the peace process will make it harder to secure the long-term commitments needed to rebuild Afghanistan when Nato operations end in 2014.