Dr. Sergio Alfieri said that as soon as he realized the Pope was in a coma, there was nothing he could do to save his life.
Many in the Jewish community felt that the Vatican, which had once pledged never to stand aside when Jews were threatened, failed to condemn a group that openly calls for the annihilation of Jews.
The following rituals mark the end of one papacy and the start of the next.
"The global Catholic community bids farewell to a leader who recognised the burning issues of our day and called attention to them," Dutch Prime Minister Dick Schoof said.
Pope Francis suggested the global community study whether Israel's military campaign in Gaza constitutes a genocide of the Palestinian people.
Francis, originally from Argentina, was the first Catholic pontiff from the Americas and began his career as a Jesuit priest in Argentina.
"I appeal to the warring parties: Call a ceasefire, release the hostages and come to the aid of a starving people that aspires to a future of peace," the Pope's Easter message said.
The 88-year-old pontiff is gradually making more public appearances as he recovers from the biggest health crisis in his 12 years in the role.
King Charles and Queen Camilla had been due to make a formal state visit to the Vatican, but postponed their plans after doctors prescribed Francis two months of rest.
The pope's official nurse pleaded with doctors to ensure that they did not stop his treatment despite significant risks.