Linking aid for countries in the Middle East and Africa to how they manage migration can create dangerous precedents, the top United Nations' refugee official warned the European Union on Monday.

 

Overwhelmed by the arrival of more than a million refugees and migrants in 2015, the EU has tightened its external borders and sought to strike deals with countries along the migration routes to contain the flow of people.

 

Under the most prominent of such collaboration, it promised Turkey an initial 3 billion euros in aid for Syrian refugees living there, accelerated EU accession talks and visa-free travel to Europe for its citizens.

 

In exchange, Ankara has increasingly prevented people from leaving its shores for Greece, which was the main gateway to Europe last year but is now much less active.

 

But, as EU's ties with Ankara soured because of the crack down there after a botched coup in July, the bloc has become more exposed Turkey's President Tayyip Erdogan threats to unleash a new wave of migrants on Europe.

 

"Support to host and transit countries should be driven by solidarity, not strict conditionality," Filippo Grandi, the U.N. High Commissioner for Refugees, told a seminar in Brussels.

 

"Caution should be exercised in linking financial aid to other benefits and migration controls. This sets precedents, raises expectations that may not always be met and can ultimately even allow host governments to use population movements as a pressure point, or even a threat."

 

Grandi, who has held the post for a year, said the deal with Turkey has also encouraged other governments to seek money from the EU for hosting refugees.

 

Brussels is now in talks with host and transit countries in Africa and has threatened to make billions worth of development aid conditional on how their handling if migration.