A million worshippers packed the Colombo seafront to greet Pope Francis as he canonized Sri Lanka's first saint on Wednesday in the biggest public celebration the city has ever witnessed.

Many had waited through the night to see the first pope to visit the island in two decades canonise Joseph Vaz, a 17th century missionary who disguised himself as a beggar to evade persecution.

Sri Lanka's former president Mahinda Rajapakse on Tuesday denied government allegations that he attempted a coup to remain in office after it became clear that he had lost last week's election.

In comments published on Twitter as Pope Francis landed on the island, Rajapakse insisted that he had readily accepted "the people's verdict" in what was his first reaction to last Thursday's polls.

Pope Francis urged respect for human rights in Sri Lanka as he began a two-nation Asia tour on the island Tuesday, bearing a message of peace and reconciliation after a long civil war.

His visit, days after the surprise election of a new president, will focus on unity in a country still struggling to heal the wounds of a decades-long civil war that pitted government troops against Tamil separatist rebels.

Pope Francis set off on Monday for a six-day trip to Sri Lanka and the Philippines, where his open-air masses are expected to draw millions.

The pope left at 7:00 pm local time (1800 GMT) from Rome's Fiumicino airport and was expected to land in the Sri Lankan capital Colombo at 9:00 am local time (0330 GMT) on Tuesday.

Washington pledged Monday to work with Sri Lanka's newly-elected government to help improve human rights and democracy, voicing hope the election will mark the start of a new chapter in ties.

U.S. Secretary of State John Kerry telephoned President Maithripala Sirisena late Sunday to say the U.S. now hoped to strengthen its ties with the tear-shaped Indian Ocean island.

Sri Lanka's new government on Sunday accused toppled strongman Mahinda Rajapakse of having tried to stage a coup to cling to power after losing last week's presidential election.

Rajapakse, South Asia's longest-serving leader before losing last Thursday's polls, had been widely praised for conceding defeat to Maithripala Sirisena before the final results had been announced.

Sri Lanka's newly-elected president has engineered enough defections from his predecessor's party to secure a parliamentary majority essential for radical constitutional reforms, officials said Sunday.

Maithripala Sirisena has already received the backing of more than 40 lawmakers who were previously loyal to Mahinda Rajapakse, whom he unseated in Thursday's presidential election, spokesman Rajitha Senaratne said.

Pope Francis will immerse himself in some of Asia's most fervent Catholicism during a trip to the Philippines and Sri Lanka starting Tuesday, with millions of devotees set to turn out.

The Argentinian pontiff with a man-of-the-people reputation could attract one of the biggest gatherings ever for a pope during an open-air mass in the Philippine capital of Manila.

New Sri Lankan President Maithripala Sirisena began assembling a cabinet Saturday on his first day in office as he looks to deliver on pledges to repair the war-torn nation's diplomatic standing and implement democratic reforms.

Sirisena, who was sworn in Friday evening after a shock election victory over veteran strongman Mahinda Rajapakse, was trying to form a "national unity" cabinet that would include members from a cross section of political parties in parliament, an aide said.

U.S. President Barack Obama praised Friday Sri Lanka's "successful and peaceful" presidential elections and congratulated the outgoing administration on a "swift and orderly transfer of power."

"Beyond the significance of this election to Sri Lanka, it is also a symbol of hope for those who support democracy all around the world," the president said in a statement.