The president of the European Council has warned that the migrant crisis could threaten the cohesion of the EU.
Donald Tusk told the European Parliament the challenge was the biggest the EU had faced for a decade.
Meanwhile Parliament President Martin Schulz accused European governments of putting national interests above finding solutions as a community.
The UN's refugee agency (UNHCR) says more than 700,000 migrants have reached Europe by boat so far this year.
EU leaders have exchanged angry accusations as authorities struggle to cope with the thousands of new arrivals, many of them refugees from Syria and other conflict zones.