SYDNEY: Pope Benedict XVI was formally welcomed to Australia by the governor-general and prime minister Thursday ahead of taking charge of Catholic World Youth Day celebrations.

The pontiff met Governor-General Michael Jeffery, the representative of Australia's head of state, Britain's Queen Elizabeth II, and Prime Minister Kevin Rudd amid tight security at Government House in Sydney.

New South Wales governor Marie Bashir and state premier Morris Iemma were also present for the start of what local media have called "Super Thursday".

Hundreds of thousands of people are expected to line Sydney's harbour and streets later for the pope's formal public arrival to lead the world's biggest Christian festival, organisers say.

A massive flotilla will line up to view a "boat-a-cade" carrying the 81-year-old pontiff across Sydney's world-famous harbour to a wharf at Barangaroo where he will address up to 150,000 pilgrims.

"We expect up to half a million including those in the venue for the pope's arrival and those lining the streets," said World Youth Day spokesman Jim Hanna.

More than 200,000 pilgrims from around the world are in Sydney for the six-day event.

World Youth Day, a celebration of the Catholic faith aimed at rejuvenating the church, has been held in a different host city around the world every two or three years since 1986.

- AFP/yb