The health of Archbishop Christodoulos, head of the powerful Church of Greece, is deteriorating and doctors say he will now receive medical treatment at home according to his own wishes.

Archbishop Christodoulos, 68, who was instrumental in improving ties between the Vatican and the Orthodox Church, was diagnosed with cancer in June and flew to Miami in August to wait for a compatible liver donor.

But an attempted transplant operation was cancelled due to his deteriorating health and the leader of about 10 million Orthodox Greeks returned to Athens for medical treatment.

"The archbishop remains at the official residence and is being treated there," a Church of Greece official said on Tuesday. "He has expressed the wish not to return to hospital."

Doctors confirmed late on Monday his health had taken a turn for the worse.

"Archbishop Christodoulos...showed a further deterioration of his clinical condition with his powers weakening," his medical team said in a statement.

Elected Archbishop of Athens and all of Greece in 1998, Christodoulos tried to mend ties with the Vatican. In 2001 he received Pope John Paul II, the first pope to visit Greece in more than 1,000 years.

The Western Church and world Orthodoxy split from each other in the schism of 1054.

Since he was diagnosed with cancer, he has only made brief public appearances, mainly outside his residence, greeted by dozens of well-wishers.