Pope Francis delivered a humor-filled speech before a congress of Bangladeshi priests and nuns in Dhaka on Saturday, capping off what was otherwise a diplomatically fraught Asian tour.

Speaking to the congregation at the Chittagong's Holy Rosary Church, Francis said he was ditching the eight-page speech he had prepared and would speak to them from the heart instead. "I don't know if it will be better or worse, but I promise it will be less boring," the pope quipped.

Read more: Rohingya refugees in Bangladesh appeal to Pope Francis

The focus of the speech saw the pontiff urge Bangladesh's religious leaders to resist the "terrorism of gossip" that threatens to tear their communities apart.

"How many religious communities have been destroyed because of a spirit of gossip?" asked Francis, before stressing that he was speaking from his own personal experience. "Please, bite your tongue."

Francis, the first Jesuit pope, has often warned of the damage gossip can do within the church and other religious institutions. He famously told the Vatican's bureaucracy in 2014 that the "terrorism of gossip" was one of the 15 maladies suffered by his closest collaborators, alongside "spiritual Alzheimer's" and a "pathology of power."

Francis mobbed by adoring nuns

Francis started his final day in Bangladesh by visiting an orphanage and home for the disabled run by Mother Teresa's order. It was there that he was mobbed by a group of nuns, all dressed in the blue-and-white saris traditionally worn by women who dedicate their lives to the region's poorest.

The pope also attended a youth rally before boarding the plane for the flight back to Rome and his traditional airborne press conference.

Pontiff points to plight of 'Rohingya'

The pope's final day in Bangladesh followed his emotional encounter with the Muslim Rohingya refugees in Dhaka on Friday.

After refraining from using the term "Rohingya" during his earlier trip to Myanmar, Francis expressed his support for the long-suffering ethnic group in no uncertain terms after landing in Bangladesh, describing them as his "brother and sisters."

"Your tragedy is very hard, very great, but it has a place in our hearts," he told them. "In the name of all those who have persecuted you, who have harmed you, in the face of the world's indifference, I ask for your forgiveness."

Read more: 'Apartheid' in Myanmar, accuses Amnesty

More than 600,000 Rohingya Muslims have crossed the border into Bangladesh since August when the Myanmar military launched a deadly crackdown. The refugees have given consistent accounts of mass rape, killings and villages being deliberately torched to the ground.

Although Myanmar and Bangladesh last month agreed to begin repatriating refugees, rights groups have warned that the Rohingya would likely be housed in camps, far away from whatever might remain of their former homes.

dm/sms (AP, AFP)