The appeal is expected to cover relief support including shelter, food, transportation, water and sanitation for up to one million people for the next three months.

"This appeal is based on planning scenario projecting up to 400,000 people leaving Libya including the 200,000 who have left to date and another 600,000 people inside Libya expected to need humanitarian aid to varying degrees," said Valerie Amos, UN aid chief.

"I hope that this appeal receives a favourable response from donors, which will enable us to continue to support those in need," added the United Nations under-secretary-general for humanitarian affairs and emergency relief coordinator. The appeal will be revised in two weeks, said the UN.