European Union officials say that member countries will never agree at the EU summit opening Thursday to plans that will oblige them to share thousands of refugees arriving in Greece and Italy.

Conflict and poverty have driven more than 100,000 migrants to Europe this year, and almost 2,000 have died or gone missing while crossing the Mediterranean Sea.

The EU wants countries to share 40,000 Syrians and Eritreans landing in Greece and Italy to ease their burden.

But a senior EU official said Wednesday that "the idea that quotas can be imposed from Brussels is not going to fly."

The official is involved in preparing a summit of EU leaders starting on Thursday when migration will be high on the agenda. He declined to be named because deliberations are on-going.