Delegates from more than 50 nations are in London for talks intended to boost Afghanistan's prospects after foreign combat forces withdraw this month.
Aid agencies working in Afghanistan are urging the international community to make long-term financial commitments or risk seeing the country collapse.
The conference comes after a recent increase in attacks by the Taliban.
President Ashraf Ghani, who took power in September, has vowed to bring peace after decades of conflict.
He is expected to use the conference to seek endorsement for his plan for a "transformation decade" from 2015-24, and guarantees that troop withdrawals will not be quickly followed by cuts in financial aid.
"As Afghanistan has a commitment to introduce reforms, it will tell the international community, in particular, donors at the meeting, that this is our agenda for reform and based on it, they should assist and support us," Presidential spokesman Nazifollah Salarzai told Afghan TV.
BBC diplomatic correspondent James Robbins says the meeting will encourage the new Afghan government to do far more than former President Hamid Karzai to tackle corruption, improve the country's security forces and demonstrate that no one is above the law.
Meanwhile, a coalition of British and Irish charities will warn the conference that a combination of cuts in their international funding and growing security fears among their staff threatens to reverse the progress that has been made.
The Taliban have intensified attacks against foreign nationals, civilians and Afghan soldiers in recent months, raising concerns over the Afghan army's ability to protect the country from insurgents.
The latest in a string of attacks targeted a compound used by a US-based charity on Saturday, killing three South Africans.
Last week, two American soldiers and two British embassy workers were killed in separate attacks, with dozens of Afghans also killed and injured.
Foreign combat troops are withdrawing at the end of the month. Some 12,000 Nato soldiers will remain for training and advisory purposes, and a separate US-led force will assist Afghan troops in some operations against the Taliban.
Among those attending the conference are UK Prime Minister David Cameron, US Secretary of State John Kerry, and Pakistani Prime Minister Nawaz Sharif.