Pope Francis called on Sri Lanka to uncover the truth of what happened during its bloody civil war as part of a healing process between religious communities, as he arrived in Colombo a few days after the island's wartime leaders were voted out.

Soon after landing in Buddhist-majority Sri Lanka, Francis appeared to make the case for a truth commission to investigate the 26-year civil war, an election pledge of the government voted into office on Thursday.

"The process of healing also needs to include the pursuit of truth, not for the sake of opening old wounds, but rather as a necessary means of promoting justice, healing and unity," he said, wearing a long garland of yellow and white flowers.

Francis was speaking at Bandaranaike international airport, where he was met by President Maithripala Sirisena, troupes of dancers and a children's choir. Sirisena said the visit was a blessing for his new government.

The pontiff departed past a long line of costumed elephants who reached their trunks towards his open-topped white jeep, which was briefly brought to a standstill by large crowds.

Francis is the first pope to visit Sri Lanka since the war ended in 2009. Fighting between the mainly Hindu Tamils and the and mostly Buddhist Sinhalese majority ended with a crushing defeat for the Tamils. A 2011 UN estimate put the death toll from the final army assault at up to 40,000 civilians.

The 78-year-old will spend two days in Sri Lanka before going to the Philippines as part of a trip aimed at shoring-up the Church's presence in developing nations. The week-long tour is his second to Asia.

The Pope carried a message of inter-faith dialogue that chimed with an unusually harmonious atmosphere in Sri Lanka, which last week elected a government promising increased respect for long-suffering religious minorities.

"My government is promoting peace and friendship among our people after overcoming a cruel terrorist conflict. We have people who believe in religious tolerance and coexistence based on centuries old religious heritage," Sirisena said.

About 70 per cent of Sri Lankans are Buddhists. Hindus make up about 13 per cent and Muslims 10 per cent. Catholics are about seven per cent, split between ethnic Sinhalese and Tamils.

HUMAN DIGNITY

Francis called for a more inclusive society in Sri Lanka, in comments that seemed directed at former president and wartime leader Mahinda Rajapaksa, who lost office after a resurgence in religious tensions.

"The great work of rebuilding must embrace improving infrastructures and meeting material needs, but also, and even more importantly, promoting human dignity, respect for human rights, and the full inclusion of each member of society," he said, speaking under the hot morning sun.

Rajapaksa is feted as a hero for ending three decades of war. He also presided over a period of fast economic growth and infrastructure reconstruction.

However, he refused to allow a fully independent inquiry into alleged war crimes and presided over a period of growing repression of religious minorities as well as political opponents.

Rajapaksa's rule coincided with isolated attacks led by hardline Buddhist monks against churches and other Christian centers.

Pope Francis had first-hand experience of devastating civil strife as a priest in his native Argentina during its "Dirty War". A 50,000 page truth report after that war revealed shocking details of kidnappings, rapes and torture by the military junta.

He also carried a message with a wider resonance in the wake of Islamist militant violence in Nigeria and France last week.

"It is a continuing tragedy in our world that so many communities are at war with themselves," he said. "The inability to reconcile differences and disagreements, whether old or new, has given rise to ethnic and religious tensions, frequently accompanied by outbreaks of violence."