The UN will meet in Geneva on Monday to raise more than $600 million for Afghanistan, warning of a humanitarian crisis there following the Taliban takeover.
Even before the seizure of Kabul last month, half of the country's population – about 18 million people – was dependent on aid. That figure looks set to increase owing to drought and shortages of cash and food, Reuters reported UN officials and aid groups as saying.
UN Secretary General Antonio Guterres said his organisation is struggling financially.
"At the present moment the UN is not even able to pay its salaries to its own workers," he said on Friday.
The Geneva conference will be attended by top UN officials including Mr Guterres, the head of the International Committee of the Red Cross Peter Maurer, as well as dozens of government representatives, including German Foreign Minister Heiko Maas.
The UN High Commissioner for Refugees, Filippo Grandi, arrived in Kabul on Monday to assess the situation.
"During my visit I will assess the country’s acute humanitarian needs and the situation of 3.5 million displaced Afghans," Mr Grandi said on Twitter.
About a third of the $606m being sought would be used by the UN World Food Programme, which found that 93 per cent of the 1,600 Afghans it surveyed in August and September were not consuming enough food, mostly because they could not get access to cash to pay for it.
"It's now a race against time and the snow to deliver life-saving assistance to the Afghan people who need it most," WFP deputy regional director Anthea Webb said. "We are quite literally begging and borrowing to avoid food stocks running out."
The World Health Organisation, another UN agency that is part of the appeal, wants to shore up hundreds of health centres at risk of closure after donors backed out.