Cuban leaders on Sunday attended the funeral Jaime Ortega, a cardinal who played a key role in improving ties between Havana and Washington during the administration of Barack Obama.
Ortega, who died at the age of 82, worked as an intermediary for Pope Francis in negotiations to ease the bad blood between Cuba and the US after five decades.
The Cold War rivals began normalizing relations in December 2014 and the next year they restored diplomatic ties.
First vice-president Salvador Valdes Mesa, vice-president Roberto Morales and Esteban Lazo, the head of the National Assembly, were at the funeral service at Havana Cathedral, an AFP journalist saw.
Cuban President Miguel Diaz-Canel and former president Raul Castro, who are visiting Venezuela, sent bouquets of flowers.
Born in 1936 in Matanzas, Ortega led the Catholic church in Cuba for 35 years before retiring in 2016.
He submitted his resignation as Archbishop of Havana in 2011 when 75, as Vatican rules required, but his close personal friend the pope refused it then, acquiescing only in 2016.
He was the facilitator in 18 months of secret talks between Cuba and the US that led to a historic thawing of relations, since reversed by President Donald Trump.
Those talks led to a prisoner exchange and Obama's historic visit to the island nation in 2016.
Garcia paid tribute to Ortega's "friendly smile, his clairvoyant intelligence and the testimony of a successful, and often painful, priesthood."