EU leaders are expected to approve a plan to distribute 120,000 migrants and refugees across Europe.
The scheme was agreed by EU interior ministers on Tuesday, despite the opposition of former communist countries Hungary, the Czech Republic, Slovakia and Romania to mandatory quotas.
Britain has an opt-out from the plan, but has agreed to take in 20,000 Syrians currently living in refugee camps in the Middle East.
Today’s meeting will be attended by David Cameron, who will press other European leaders to increase aid to countries bordering Syria and deport migrants who do not have valid asylum claims.
The current crisis has been caused by a surge in migrants arriving from the Middle East, many of them Syrians, and North Africa.
Conflict in Afghanistan, civil war in Syria and a repressive regime in Eritrea are seen as major factors in what has been described as the worst refugee crisis since the Second World War.
A number of countries have come under strain, including Greece, Italy, Hungary and Croatia, while Europe is divided on how to deal with the issue.
Germany has agreed to accept 800,000 migrants and refugees this year, but has been criticised by some for encouraging people to travel to Europe.
The EU had hoped to achieve unanimity at Tuesday’s meeting of interior ministers, but when this proved impossible, took the unusual step of approving the quota plan on a majority basis.
Slovakia said it would go to court to challenge the quota plan – a course of action ruled out by the Czechs – and would not implement it. Romania said the number of migrants and refugees it was expected to take in was “manageable”.
French President Francois Hollande said there would be consequences for countries that failed to abide by the agreement.
Governments can be fined by EU courts for failing to implement European law, and ministers in some western countries have warned that they could reduce future subsidies to poorer neighbours that do not show “solidarity” in the refugee crisis.
President Hollande told French TV station BFMTV: “You cannot ask Europe for support and refuse when Europe asks for solidarity.”
The UN refugee agency said the quota plan “will not be enough to stabilise the situation”. It is calling for additional measures, including the immediate creation of new reception facilities in Greece and strengthened mechanisms to return those who are not granted asylum.