The order from President Recep Tayyip Erdogan comes a week after he said he was “opening the doors” for refugees to enter Europe, amid tensions over the Syrian conflict.
The EU accuses him of using migrants for political purposes. It insists its doors are “closed”.
Meanwhile, clashes have again erupted at the land border.
There appears to have been no change in Turkey’s position with regard to letting migrants try to enter Greece via this route.
On Saturday, Greek police fired tear gas at crowds at the border crossing at Kastanies, who responded by throwing stones and shouting “open the gates”, according to the AFP news agency.
The Greek authorities also accused Turkish police of firing tear gas at its police.