The European Commission is due to unveil options for reforms to the way EU countries handle asylum claims in response to the migrant crisis.
The move is in part a reaction to the difficulties faced by Greece and Italy to cope with thousands arriving from the Middle East and Africa.
Other countries meanwhile have taken in hardly any refugees.
Separately, people in the Netherlands are taking part in referendum on an EU free trade deal with Ukraine.
They will be given the choice of voting for or against ratification of the deal.
Correspondents say the non-binding referendum is being viewed by many as an opportunity to protest against the EU’s expansion and what they consider to be its undemocratic decision-making processes.
Some campaigners see it as a precursor of the UK’s June referendum on EU membership.
Under a Netherlands law from last year that created advisory referendums, the result is valid only if turnout is more than 30%.
If a majority votes against the deal, the government can introduce new legislation which in effect would cancel its ratification. Likewise if there is a vote in favour it can advise parliament to uphold the ratification, reports the BBC.
EU Commission President Jean-Claude Juncker has described the stakes in the run-up to the vote as being high, warning that a “No'” vote could trigger a wider crisis in the 28-member bloc.
BBC Europe Correspondent Damian Grammaticas says that under the current system for dealing with migrants, known as the Dublin Regulation, countries have the power to return asylum seekers to the first EU state they entered for their claim to be dealt with there.
The British government is one of several countries that do not want to see wholesale changes to the system.
But the influx of more than a million people to Europe last year has made the flaws in the EU’s asylum system obvious, our correspondent says.
