The International Organization for Migration (IOM) and the U.N. Refugee Agency (UNHCR) urged a return of European Union countries' search and rescue vessels, aimed at assisting people trapped in Libya or at risk of dying on the Mediterranean Sea.

"In the past European state vessels conducting search and rescue operations saved thousands of lives, including through disembarkations in safe ports," the IOM and UNHCR noted in a statement on Thursday. "They should resume this vital work and temporary disembarkation schemes should urgently be established to share responsibilities within Europe. NGO boats have played a similarly crucial role on the Mediterranean and must not be penalized for saving lives at sea."

In 2014, the EU's border control agency, Frontex, decided to end the Mare Nostrum rescue operation. In one year, the operation rescued 150,810 migrants in the Mediterranean as hundreds of thousands crossed the sea. It was replaced by an operation named Triton, conducted from November 2014 to February 2018, and financed by all 28 EU nations at a fraction of the cost. But unlike the earlier program, the new rescue operation has been criticized due to the fact that the main focus of this joint EU mission is only to manage border security control to keep the massive number of migrants away from coming to Europe. Deaths in the Mediterranean then soared. In 2014, around 3,200 migrants died in the sea. The following year, it rose to over 4,000, and in 2016 peaked at over 5,100 deaths and disappearances, according to figures from the IOM.

Since then, some independent rescue operations by nongovernmental organizations (NGOs) have attempted to fill the void left after EU efforts ceased, while struggling to save many migrants' lives despite some EU government's hard-line policies of closing their harbors to humanitarian groups' rescue ships. Both Italy and Malta have impeded aid groups from operating rescue boats, either by refusing them entry to their ports or by impounding their vessels and putting their crews under investigation. Italy's migration policy is deepening rifts in Europe as NGOs clash with Italian authorities over rules that effectively close off the country's ports to their boats. Italy's coalition government, which includes the right-wing League, blames European partners for leaving it alone to deal with sea arrivals. New rules were adopted last month threatening NGO ships entering Italian waters without permission with a fine of up to 50,000 euros (approximately $56,280) and the impounding of their vessels.