The mass inside Saint Peter's Basilica at the Vatican came after several appeals for peace in recent months by Francis, who visited Myanmar in November 2017, marking the first papal visit to a Buddhist-majority nation.

A Myanmar nun recited the first reading in Burmese in front of a congregation of about 200 nuns, priests and seminarians during the mass intended for the country's Catholics in Rome and beyond.

Myanmar has been in chaos since the military ousted civilian leader Aung San Suu Kyi in a February 1 coup, triggering a massive civilian uprising that security forces have sought to quell with lethal force.

Street protests calling for a return to democracy continue to occur nearly daily, despite the junta's bloody crackdown having killed an estimated 790 people to date, according to a local monitoring group.

In his homily, Francis skirted an overt denunciation of the military regime, instead appealing to the faithful to be "steadfast in the truth," urging them not to lose hope.

"Dear brothers and sisters, in these days when your beloved country of Myanmar is experiencing violence, conflict and repression, let us ask ourselves: what we are being called to keep? In the first place, to keep the faith," he said.

Francis appealed for unity, calling division among communities and peoples "a deadly disease."

"Sins against unity abound: envy, jealousy, the pursuit of personal interests rather than the common good, the tendency to judge others. Those little conflicts of ours find a reflection in great conflicts, like the one your country is experiencing in these days," he said.

"I know that some political and social situations are bigger than we are," he added. "Yet commitment to peace and fraternity always comes from below: each person, in little things, can play his or her part."

"Amid war, violence and hatred, fidelity to the Gospel and being peacemakers calls for commitment, also through social and political choices, even at the risk of our lives."