ATHENS, Greece (AP) — Greek authorities say they will start a gradual evacuation of the country's main informal camp for refugees and other migrants within the next few days.

Police and government officials said Monday the estimated 8,400 people at Idomeni, on the closed northern border with Macedonia, will be sent to newly-completed, organized camps.

Government spokesman Giorgos Kyritsis says the operation should start Tuesday or Wednesday.

Greece has been trying for months to persuade Idomeni camp residents to move. About 54,000 migrants have been stuck in Greece since a series of Balkan border closures in March.

Kyritsis said 6,000 places are available in new camps, and more will be ready soon. He insisted force will not be used.

Riot police units were being moved Monday from other parts of Greece to Idomeni.