Greece recorded 65 more cases of the novel coronavirus on Thursday -- the steepest increase since May 4.
Seventeen of the patients were identified at check-in areas at airports and other border stations, health authorities said.
Total deaths remained at 203 on Thursday, while the overall case tally rose to 4,401, of which the 1,250 were related to overseas travel, according to data compiled by the National Public Health Organization (EODY).
At the Maximos Mansion in the capital Athens, Prime Minister Kyriakos Mitsotakis said at a virtual meeting with scientific staff: "If you judge that you need to sound the alarm for some measures to be taken, do not hesitate to do this promptly."
The meeting focused mainly on the need to intensify checks and inspections on public transport and entertainment venues.
On Tuesday, Greek authorities announced expanded measures for mandatory face masks.
