UN Secretary-General Ban Ki-moon has expressed his deep sadness about the crash of Egypt Air's flight MS804, according to a statement by his spokesman.

"He sends his heartfelt condolences to the families of the victims and to the governments and peoples affected by this tragedy," the Friday statement read.

The spokesman added that the UN secretary-general is "grateful to those who have joined the recovery operations for their quick response."

The statement comes after Egypt's civil aviation ministry said debris and "body parts" were recovered on Friday by Egyptian search teams from a site in the Mediterranean where the Airbus 320, which was flying from Paris to Cairo, is assumed to have crashed.

The jet disappeared from radar screens shortly after entering Egyptian airspace early on Thursday morning. All 66 on board are presumed to have perished.

The ministry said the Egyptian army and navy had found body parts, luggage, passengers' personal belongings, and plane seats.

Later on Friday, the European Space Agency said that one of its satellites had detected a possible oil slick in the Mediterranean Sea in the same area where the Airbus vanished.

However, the agency said that there was no "guarantee the slick is from the missing aircraft."

EgyptAir has said it has formed a committee to investigate the crash, adding that the Airbus representative is taking part in the investigation.

Three French investigators and a technical expert from Airbus arrived in Cairo early on Friday to assist in the investigation.