A total of 514 migrants arrived on the Greek Aegean islands from Turkey in the 24 hours to Sunday morning, officials said, the day before a deal to return such migrants to Turkey goes into effect.
On Saturday, the figure was 566 migrants, on Friday 339 and on Thursday 377, the Greek department dealing with the refugee crisis said.
The department said that as of Saturday there were more than 52,500 refugees and other migrants stranded in Greece after countries further along the so-called Balkan route to northern and western Europe closed their borders to people without valid documents.
On Monday, the deal between the European Union and Turkey to send back to Turkey from the Greek islands of Lesbos and Chios any migrants unlikely to gain asylum comes into effect.
Migrants likely to be sent back have protested, denouncing the returns as "deportations." Hundreds of them broke out of a camp on Chios on Friday and were camped out in the island's main port on Sunday. They demanded to be taken to the mainland of Greece and not back to Turkey.
Meanwhile, the site in Dikili in western Turkey, just north of Izmir, where the returnees are meant to be accommodated remained an empty, grassy field on Sunday, mobile phone shots received by dpa showed.
The Turkish prime minister's office refused to answer questions posed by dpa on the government's preparedness to receive the returnees.
The Turkish government did reject accusations from Amnesty International that it was sending large number of refugees back to Syria.
"It is not the case that Syrians are being encouraged to return voluntarily to their country or that they are being forced to do so," a statement from the Turkish Foreign Ministry said on Sunday.
Turkey was determined to continue to offer Syrian refugees protection, it said.
Turkey is currently accommodating some 2 million refugees from Syria.