Overcrowded, open camps that have become home to 33,000 asylum seekers on five Aegean islands are to be shut down and replaced with closed centres.
Four or five new sites will be set up to house 1,000 to 5,000 people.
Conditions are so bad at camps such as Moria and Vathy that a Council of Europe commissioner spoke of an “explosive situation” and a struggle for survival last month.
Greece has seen a big rise in migrant numbers crossing from Turkey.
The proposed sites are being described as “closed pre-departure centres”, an announcement which the government in Athens hopes will be noticed by traffickers and potential asylum seekers alike.
“A clear message should be sent to those planning or thinking of coming to the country illegally when they aren’t entitled to asylum,” said government spokesman Stelios Petsas.
The government is also promising tighter sea and land borders, and a faster asylum process.