French President Francois Hollande says his country will welcome 24,000 refugees.

In a speech ahead of a wide-ranging press conference, the Socialist says taking in those fleeing war is a duty that France is ready to shoulder.

He said he and German Chancellor Angela Merkel had agreed upon a mechanism to distribute refugees across Europe.

Meanwhile, Ms Merkel said Germany will ensure that those who need protection receive it, but that those who stand no chance of getting asylum will have to return to their homes swiftly.

She also stressed that Europe's biggest economy isn't willing to shoulder the whole refugee burden alone, saying that "Germany is a country willing to take people in, but refugees can be received in all countries of the European Union in such a way that they can find refuge from civil war and from persecution."

Greece has requested emergency EU assistance to deal with the massive influx of refugees and migrants who reach its eastern islands daily on frail boats from nearby Turkey.

More than 230,000 people have arrived so far, at a rapidly increasing pace, and have overwhelmed authorities in the financially struggling country that has become Europe's main gateway for migrants.

The Interior Ministry said it has applied for activation of a European mechanism for civil protection assistance, which it said would be of "crucial importance" in improving migrants' reception facilities - which are, at best, rudimentary.

A ministry statement said Greece has provided detailed information on what it needs in terms of medical and pharmaceutical supplies, equipment for reception centres, clothing and personnel