The U.N. High Commissioner for Refugees says 700,000 asylum-seekers will reach Europe via the Mediterranean this year and it projected that approximately the same number will arrive in 2016.
The UNHCR almost doubled the estimate of the migrant and refugee influx into Europe in 2015. It also appealed for $128 million in donations to cope with the refugee crisis, a much higher sum than the $30.5 million it requested last month.
The agency said more than 520,000 people, more than half from Syria, have reached Europe this year, while close to 3,000 people have died during the attempt.
Meanwhile, Greek authorities have opened a disused Olympic venue to house more than 400 migrants who have been camping out in Athens' Victoria Square.
Police on Thursday escorted buses carrying the migrants, many from Syria and Afghanistan, to Galatsi Olympic Hall. The venue was home to table tennis and gymnastics competitions during the 2004 Olympics.
City officials have been trying to ease citizens' concerns about the number of migrants camping out in the open in central Athens. Greece is on the front lines of the European migrant crisis and has been overwhelmed with people who travel across the Mediterranean Sea from the Middle East and Africa to seek better lives in the European Union.
At the U.N. General Assembly in New York on Wednesday, Secretary-General Ban Ki-moon appealed to the world to approach Europe's refugee crisis with "creativity, compassion, and courage."
Ban told a meeting of 70 ministers at the General Assembly that "the future does not belong to those who seek to build walls or exploit fears."
He stressed the need for cooperation among all those who are struggling to cope with the crisis, with all efforts focused on saving lives. Otherwise, Ban said, "the winners will be smugglers, traffickers and unscrupulous employers. Those who lose will be the dispossessed, the hungry, the vulnerable, the defenseless, and the children."