Antonis Samaras underwent surgery for a detached retina Saturday. Government spokesman Simos Kedikoglou said Sunday that the doctor treating him had forbidden him from flying.
Kedikoglou said newly appointed Foreign Minister Dimitris Avramopoulos would attend the June 28-29 summit in Samaras place.
Greece's incoming finance minister, Vassilis Rapanos, was also hospitalized Friday after suffering a collapse. As his swearing in had to be postponed outgoing Finance Minister Giorgos Zanias still holds the title.
Zanias, who was a key negotiator for Greece's bailout deal before being named to the post, will also attend the summit, along with two deputy ministers.