An ailing Pope John Paul II has arrived in Canada to begin his 97th overseas trip, slowly descending the stairs from his plane at Toronto's Pearson International Airport.

Despite health concerns, the 82-year-old Pope is making a 10-day trip that will see him preside over the Roman Catholic World Youth Day festivities in Toronto before heading to Guatemala and Mexico.

After being greeted by Canadian Prime Minister Jean Chretien and his wife Aline, the Pope spoke in both French and English - Canada's two official languages - at a ceremony in a nearby hanger.

He praised Canada for its tolerance and diversity as a "temple of human rights", and said the hundreds of thousands of young people expected to take part in the World Youth Day festival were "the future of the world".

The Pope suffers from Parkinson's disease and arthritis

He also said that Canada's founding on Christian principles "gave vital impetus to your development as a free, democratic and caring society".

About 45% of Canada's population is Roman Catholic.

After Canada, the Pope's itinerary will take him to Guatemala and Mexico, where he is due to canonise local figures.

Concerns about the Pope's health have mounted in recent months. He suffers from Parkinson's disease and severe arthritis, and has spent the past two weeks resting in his summer residence at Castel Gandolfo outside Rome on the advice of doctors.

The Vatican has also scheduled several rest days in the Pope's itinerary.

After arriving in Toronto, the Pope flew by helicopter to Strawberry Island, a Catholic retreat about 95km (59 miles) north of the city on Lake Simco.

Crowds gathered at the Canadian National Exhibition fairgrounds to watch the Pope's arrival remotely, on a big screen, and cheered as he made it down the stairs with the help of an aide.

Security concerns

More than 200,000 people from 173 countries are expected to participate in Thursday's World Youth Day, a biennial event where young Catholics from across the globe gather to celebrate their faith.

Organisers say many people have been deterred from attending due to fears of terror attacks following 11 September and the current economic downturn.

Security in the Canadian city has been tightened, with extra officers drafted to monitor the crowds.

The Pope's Canadian visit, his third, will culminate in a huge open-air mass on Sunday. He has previously visited Canada in 1984 and 1987.