GENEVA, Jan 11 (Reuters) - U.N. agencies on Tuesday asked donors for $4.4 billion in humanitarian aid for Afghanistan in 2022, calling the funds an "essential stop gap" to ensure the country"s future after a period of turmoil marked by the Taliban"s seizure of power and a hasty U.S. exit. The United Nations says the appeal, which amounts to nearly a quarter of the country"s GDP, is the largest ever sought for a single country and is triple the figure it received in 2021 when the U.S.-backed government collapsed. "This is a stop gap, an absolutely essential stop gap measure that we are putting in front of the international community today," U.N. aid chief Martin Griffiths told reporters in Geneva. "Without this being funded there won"t be a future, we need this to be done otherwise there will be outflow, there will be suffering." The abrupt withdrawal of foreign aid last year following the Taliban victory in August left Afghanistan"s fragile economy on the brink of collapse, with food prices rising rapidly and causing widespread hunger. Western sanctions aimed at the Taliban also prevented the passage of basic supplies of food and medicine, although this has since eased after exemptions were passed by the U.N. Security Council and Washington in December. read more Griffiths, who has been meeting with Taliban officials, said the humanitarian plan had been "carefully calibrated" so that aid will go directly to people in need and not to authorities. Filippo Grandi, U.N. High Commissioner for Refugees, said that improved security presented an opportunity to entice millions of people displaced by the long conflict back home, adding that since the Taliban seized power, 170,000 had returned already. "The conflict between the Taliban and the previous government is over and that has opened up some space of security which I think we need to take advantage of," Grandi said. "But to do that we need those resources that are part of this appeal."