The UN's global humanitarian appeal, which has been revised up to 21.6 billion dollars for this year, is only 25 per cent funded as the middle of the year approaches, the UN warned Monday, according to dpa. The appeal, which was changed from the previously projected 19.7 billion dollars, has received 5.5 billion dollars from international donors, UN humanitarian affairs chief Stephen O'Brien said in a statement, noting that it marked the highest amount ever received by mid-year. "The generosity of our donors is not in dispute," O'Brien said. "Nonetheless, we are facing a funding gap of 16.1 billion dollars, due to the unrelenting exponential growth of humanitarian need." The UN aims to reach 95.4 million people with humanitarian assistance this year - an upward estimate of people in need from 86.6 million in December. The funds are intended to assist people living in areas with protracted conflicts, including Syria, the Central African Republic, Iraq and South Sudan; and those affected by natural disasters, such as severe droughts in Ethiopia and Zimbabwe induced by the El Nino phenomenon.