EU leaders are bitterly divided over a quota scheme for housing migrants, as they gather for a summit in Brussels.
Summit chairman Donald Tusk irritated an EU commissioner and some other officials by calling mandatory quotas “ineffective” and “highly divisive”.
His European Council agenda calls for an EU deal by June to ease the burden on Mediterranean countries facing the greatest migrant pressure.
Poland and three neighbours in Central Europe reject the EU’s asylum policy.
Slovakia is the fourth member of the Visegrad Group, which collectively opposes quotas.
The pre-summit agenda sent to leaders by Mr Tusk – a former Polish prime minister – appeared to back those countries’ objections. They argue that they are ill-equipped to integrate people from non-Christian cultures who would rather live in richer EU countries anyway.
“The issue of mandatory quotas has proven to be highly divisive and the approach has received disproportionate attention in light of its impact on the ground; in this sense it has turned out to be ineffective,” the agenda said.
The European Commission devised a mandatory scheme to relocate 160,000 refugees – Syrians and Eritreans – from Italy and Greece to other EU countries. But so far only about 32,000 refugees have been transferred.
The Commission’s migration chief, Dimitris Avramopoulos, called Mr Tusk’s position “unacceptable” and “anti-European”.
Read more on the migrant crisis:
Asylum reform plan
The EU is still struggling with the aftermath of the 2015 migrant crisis, when more than a million people – many of them fleeing the wars in Syria, Iraq and Afghanistan – sought asylum in Europe.
Boatloads of migrants crossing the Mediterranean have stretched resources in Italy and Greece to their limits. The influx subsided this year, however, as the EU tightened co-operation with authorities in Libya and Turkey, the key transit countries.
Italy’s Prime Minister Paolo Gentiloni will discuss the migration challenge with those leaders most critical of quotas. Then the 28 member states will try to find common ground on the troubled asylum policy over dinner.
Italy and Germany are among the countries that want mandatory quotas, so that migrants can be relocated at times when there is a surge of migration into the EU.
There is consensus that the EU’s Dublin system, stipulating that an asylum seeker’s claim should be handled by the country where he or she first arrived in the EU, puts too much pressure on Italy and Greece.
A note on terminology: The BBC uses the term migrant to refer to all people on the move who have yet to complete the legal process of claiming asylum. This group includes people fleeing war-torn countries such as Syria, who are likely to be granted refugee status, as well as people who are seeking jobs and better lives, who governments are likely to rule are economic migrants.