EU ministers are to meet and try to resolve a dispute over how to relocate 120,000 asylum seekers who have recently arrived in Europe.
A group of central European states is resisting calls for 22 EU members to accept mandatory quotas.
Hungary, which takes one of the strongest lines on the issue, has said European borders are under threat.
The arrival of hundreds of thousands of migrants has exposed deep divisions within the EU.
Home affairs ministers meeting in Brussels on Tuesday will be hoping to forge a consensus ahead of an emergency meeting of EU leaders on Wednesday.
After talks on Monday between Hungary, Poland, Slovakia and the Czech Republic, all of whom oppose quotas, Czech Foreign Minister Lubomir Zaoralek insisted the four were still "absolutely dedicated" to finding a solution.