The head of the U.N. refugee agency says returns home among the millions of Syrians living abroad are few, and insists that rescues on the Mediterranean Sea have been "taken hostage by politics" — and must be restored.

Filippo Grandi also urged Myanmar's government to do more to create the conditions for Rohingya Muslims to return home. Hundreds of thousands of Rohingya have fled to neighboring Bangladesh to escape a bloody crackdown since August last year.

The wide-ranging address by Grandi at UNHCR's annual executive committee meeting on Monday comes as the European Union has been riven by discord over how to handle an influx of migrants in recent years — though the rate has dropped off from a record high in 2015.

The new government in Italy, which has taken a stricter line on migrants, has refused to allow in some boats that retrieved desperate people who left from Libya, dropping the dilemma of whether to take them in on fellow EU countries like France and Spain.

Grandi, who is Italian, appealed to Europe to preserve its asylum policies. He noted that Libya — the main launch point for migrants hoping to cross the Mediterranean — has strengthened its coast guard in recent months, but not its other institutions.

As a result, more would-be migrants and refugees have been getting forcibly returned to Libya, and "that means more and more people exposed to exploitation and detention — in horrific conditions."

"Responsibility-sharing has been replaced by responsibility-shedding," Grandi said, alluding to the EU squabbles. "Pushing people away cannot be the answer, and negotiating disembarkation boat by boat, even when successful, is not a good option."

Hotspots like Syria and Myanmar also top the U.N. High Commissioner for Refugees' agenda.

Grandi cited estimates that some 750,000 internally displaced people in Syria have returned home this year, but that less than 1 percent of people who fled the country are returning each year.

He said the direction of Syria's war in the coming months, notably in rebel-held Idlib, will be a key factor in determining the decision-making of some 5.6 million Syrian refugees.