A total of 1,662 migrants have landed on Greek islands near Turkey since a landmark EU-Turkish deal on curbing the influx took effect on Sunday, a Greek coordination panel said Monday.

Half of the migrants - 830 - arrived on Chios and 698 on Lesbos, two islands in the northeast Aegean which lie close to Turkey, according to the SOMP agency which is coordinating Athens' response to the migration crisis.

The continuing influx "creates a problem and raises questions about the intent of all parties" in the agreement, SOMP spokesman Giorgos Kyritsis said.