GENEVA (Reuters) - The International Organization for Migration (IOM) issued an urgent appeal for $24 million on Thursday to help support the more than 5 million people displaced in Afghanistan and living in "extremely precarious" conditions.

       The call came as the United States and allies urged Afghans to leave Kabul airport, citing the threat of an attack by Islamic State militants, as Western troops hurry to evacuate as many people as possible before an Aug. 31 deadline.

       "Our humanitarian activities continue where possible, depending on access and security. Large-scale displacement driven by conflict and drought, and exacerbated by the COVID-19 pandemic, are increasing poverty and food insecurity, generating massive humanitarian and protection needs in the country," IOM Afghanistan Chief of Mission Stuart Simpson said in a statement.

       Priorities included providing shelter, water, sanitation and hygiene for the 5.5 million internally displaced people in Afghanistan, including more than 550,000 newly displaced in 2021, almost half of whom fled their homes since July, it said.

       At the start of this year, half of Afghanistan's 40 million people already required humanitarian assistance, including 10 million children, with needs expected to rise, the IOM said.

       (Reporting by Michael Shields; Editing by Alex Richardson)