Greek Prime Minister Alexis Tsipras is meeting Turkish leaders for talks centering on stemming the flow of migrants crossing from Turkey into Greece.
The talks on Wednesday come as Greek authorities are struggling with the influx of refugees and economic migrants reaching Greek islands from Turkey. The discussions have gained added urgency over indications that one of the Paris attackers may have passed through Greece in October.
More than 600,000 people have reached Greece so far this year. Hundreds died when their overloaded boats sank or capsized.
On Tuesday, Tsipras and Turkish Prime Minister Ahmet Davutoglu watched a soccer match between their countries' national teams, marred by Turkish fans' booing of the Greek national anthem and of a minute of silence in remembrance of the Paris victims.