Brussels (AFP) - The EU has until a March 7 summit with Turkey to curb the number of migrants coming to Europe or else the bloc's migration system might "completely break down", migration commissioner Dimitris Avramopoulos said Thursday.

"In the next 10 days, we need tangible and clear results on the ground. Otherwise there is a risk that the whole system will completely break down," Avramopoulos told a press conference after interior ministers dealing with the crisis met in Brussels.

The EU official also warned of an imminent humanitarian crisis in Greece, the main arrival point for migrants in Europe, or on the western Balkans route most take to richer northern European countries.

"The situation is very critical. The possibility of a humanitarian crisis is very real and very near," Avramopoulos said.

The EU-Turkey summit promises to be crucial, both for the deal that Brussels and Ankara signed in November to cut migrant flows, and for the unity of the European Union on coping with the biggest such crisis in its history.

Avramopoulos urged EU states to work together and avoid "unilateral actions", such as the border controls that several countries have reintroduced and caps on asylum seeker numbers brought in by Austria which have left thousands of refugees stranded between member states.

The border controls threaten Europe's Schengen free travel area that spans 26 countries.

"We cannot continue to deal through unilateral, bilateral or trilateral actions; the first negative effects and impacts are already visible," Avramopoulos said.

"We have a shared responsibility –- all of us -– towards our neighbouring states, both EU and non-EU, but also towards those desperate people."