About 100 countries and international organizations will be represented at the Monday gathering, with some 60 foreign ministers in attendance, among them US Secretary of State Hillary Rodham Clinton.
But one of the most important countries for Afghanistan's future, its eastern nuclear-armed neighbour Pakistan, said it will boycott the conference to protest last month's NATO air assault carried out from Afghan territory that killed 24 Pakistani soldiers.
Pakistan is seen as crucial player in the region because of its links and influence on insurgent groups that are battling Afghan government and foreign troops and that sometimes use Pakistan as a base for their operations.
The Bonn conference is expected to address the transfer of security responsibility from international forces to Afghan security forces over the next three years, long-term prospects for international aid and a possible political settlement with the Taliban.
"Our objective is a peaceful Afghanistan that will never again become a safe haven for international terrorism," German Foreign Minister Guido Westerwelle said.
The US had once hoped to use the Bonn gathering to announce news about the prospect for peace talks with the Taliban, but neither an Afghan nor a US outreach effort has borne fruit.
The reconciliation efforts suffered a major setback after the September assassination of former Afghan President Burhanuddin Rabbani, who was leading the Afghan government's effort to broker peace with the insurgents.
But Washington and other partners are still trying to arrange an interim step toward talks, the opening of a Taliban diplomatic office where its representatives could conduct international business without fear of being arrested or killed. Such a deal would be a minor accomplishment for the Bonn gathering.
"Right now we don't know their address. We don't have a door," to knock on, said Afghanistan's ambassador to the US, Eklil Hakimi.
The final declaration of the Bonn conference is expected to outline broad principles and red lines for the political reconciliation with the Taliban, a project that several leading participants in the conference increasingly predict will outlast the NATO timeline for withdrawal in 2014.
The Bonn conference also seeks to agree on a set of "mutual binding commitments" under which Afghanistan would promise reforms and policy goals such as good governance, with donors and international organisations pledging long-term assistance in return to ensure the country's viability beyond 2014, a senior German diplomat said.
"It's about not repeating the mistakes of 1989, when the Soviet troops left and the West also forgot about Afghanistan," he said, referring to the bitter civil war that unfolded soon after the sudden withdrawal that was followed by the collapse of the Soviet Union.