Earlier in the day, the Al Mayadeen TV channel reported, citing airline sources that the passenger jet went down into the Mediterranean.
"Flight MSR 804 went missing 7NM within Cairo FIR. We have no information yet, the flight is considered missing," Lintzerakos said, commenting on whether it can be confirmed that the plane fell into the Mediterranean Sea.
Greece's search and rescue efforts in full coordination with the Egyptian authorities are still in progress, he added.
Egypt Air Flight MS804 departed from the Charles de Gaulle Airport in Paris at 23:09 GMT. The aircraft was heading for Cairo International Airport. According to the airline, there were a total of 66 people on board the plane, including 56 passengers.
The Egyptian military received a distress signal from the MS804 passenger plane at 4:26 a.m. local time over the Mediterranean Sea, the Egyptian Ministry of Civil Aviation said in a statement.
Egyptian Prime Minister Sherif Ismail has already arrived at the airport of Egypt to monitor the situation with the EgyptAir jet.
French President Francois Hollande is also due to hold an interdepartmental ministerial meeting on Thursday over the aircraft's disappearance.
According to EgyptAir, the making year of the Airbus A320 aircraft is 2003. The plane's pilot has over 6,200 flying hours, including over 2,100 on Airbus 320, while the co-pilot has over 2,700 flying hours.