In a communique published at the end of the conference, which was attended by delegates from 70 countries, support was also offered for the continued growth and expansion of the Afghan national army and police force.
Delegates agreed a target of recruiting some 171,600 soldiers and 134,000 police officers by October 2011.
But Hillary Clinton, the US secretary of state, said that plans to gradually transfer Afghan security from international to domestic forces were "not an exit strategy".
"We ... support the Nato transition plan," Clinton said. "But I want to make clear - to Afghans, to our partners, to our citizens, and to the extremists who hope for our failure: This is not an exit strategy."
Taliban dismissed the London conference as a propaganda ploy, saying the summit would fail to produce results, according to the AFP news agency, quoting an internet statement.
"The war-mongering rulers under the leadership of [US president Barack] Obama and [British prime minister Gordon] Brown want to deceive the people of the world by holding the London conference to show that people still support them".
If the decision is taken to "once again try to prolong the military, economic, cultural and political occupation of [Afghanistan], this conference will be mere wishful thinking like other conferences."
The statement also dismissed a plan by Hamid Karzai, the Afghan president, to woo Taliban moderates with offers of money and jobs.
"They announce that they will provide money, employment and opportunity to have a comfortable life abroad for those mujahedeen who agree to part ways with jihad," the statement said.
"This is baseless and futile," it said. "Had the aim of the mujahedeen of the Islamic Emirate been obtainment of material goals, they would accept dominance of the invaders in the first place."
Earlier on Thursday, Karzai said that his country must reach out to its "disenchanted brothers" in an effort to stabilise the war ravaged nation, saying fighters who are "not part of al-Qaeda or other terror groups" must be reconciled with the government.
The Afghan leader said his government would set up a national council for peace and reconciliation, and has asked Saudi Arabia to help guide the process.
Karzai was seeking support for a $1 billion plan that would offer cash, jobs and other incentives to the Taliban and fighters in other armed groups, in an attempt to bring them back into mainstream society.
Taliban fighters have also been invited to a "peace jirga", or a traditional gathering of tribal elders, expected to be held early this year, a government spokesman confirmed.
Hamid Elmi, Karzai's deputy spokesman, said: "We are using all kinds of possibilities - our neighbouring countries, the international community, the king of Saudi - to encourage the Taliban to come".
|Whether Taliban would accept an invitation to a 'peace jirga' is a moot point.
However, Saudi Arabia said on Thursday that it would only take part in Afghan peace efforts if the Taliban denies sanctuary to Osama bin Laden, the al-Qaeda leader, according to the kingdom's foreign minister.
"Unless the Taliban give up the issue of sanctuary [to bin Laden] I don't think the negotiations with them will be possible or feasible to achieve anything," Prince Saud al-Faisal told reporters on the sidelines of a London conference.
"We have two conditions: that the request comes officially from Afghanistan and the Taliban has to prove its intentions in coming to the negotiations by cutting their relations with the terrorists and proving it."
But Haroun Mir, deputy director for the centre for research and policy studies in Kabul, told Al Jazeera that Karzai's proposal could be hampered by plans to increase the number of foreign troops in Afghanistan.
"Karzai has been talking for a long time for reaching out to the Taliban.
"But ... the US military surge and additional Nato forces in Afghanistan in the coming months [will see] the intensity of fighting increase.
"I don't know how president Karzai could implement his own strategy of reaching out to the Taliban if there is increased fighting going on in Afghanistan," he said.
And Abdullah Abdullah, the presidential candidate who withdrew from last August's fraudulent elections, said obstacles remain to implementing such a policy.
"I don't think the Taliban at this stage are willing to enter negotiations. Also, their association with terrorist organisations, like al-Qaeda - that's the main issue at the moment - and they are working like one organisation."
Thursday's conference comes nearly a week after a meeting between Afghan government officials and members of an armed opposition group fighting alongside the Taliban.
Al Jazeera's David Chater, reporting from Kabul, said the talks were held with the group Hezb-e-Islami, in the Maldives islands, between January 23-24.
He said a Taliban leader had been due to attend the meeting but dropped out in the last minute citing health reasons.