"The European Union response needs to go beyond the present minimalist approach... which focuses primarily on stemming the arrival of migrants and refugees on its shores," Reuters quoted them as saying in a joint statement ahead of a summit of EU leaders in Brussels.
The statement was co-signed by the UN human rights and refugee agency chiefs Zeid Ra’ad Al Hussein and António Guterres, UN special representative for migration Peter Sutherland and William Lacy Swing, head of the International Organization for Migration.
The UNHCR estimates 3,500 migrants died in the Mediterranean last year, up from 600 in 2013. With few bodies recovered, many deaths are never officially confirmed. Instead, their fates are recounted by survivors and, in cases when boats are lost at sea without any rescue attempt, by relatives who report their failure to arrive in Europe.
Rights groups have criticized the EU for scrapping rescue operations in the Mediterranean, saying it had endangered the lives of thousands of desperate migrants making perilous journeys across the sea.