German-Polish reconciliation is a theme of the Pope's visit

There was choral singing and applause to mark his arrival, while the streets of Warsaw were festooned with the flags of Poland and the Vatican.

Speaking in Polish, the German-born Pope said he had "come to follow in the footsteps" of John Paul II.

On Sunday he will visit the Nazi German extermination camp at Auschwitz.

More than a million people - mostly Jews - died at the camp, where the Pope will pray for reconciliation between nations and faiths.

I so wanted to visit the country of my beloved predecessor Pope Benedict XVI In pictures: Pope's visit Memories stirred in Warsaw

Pope Benedict, who was once a reluctant member of the Hitler Youth, will walk, not drive, through the notorious death camp gates, and will refrain from speaking German during the visit.

On the way from the airport to St John's Cathedral in Warsaw he made a detour in his Popemobile to pass by the site of the 1943 Warsaw ghetto uprising, honouring the Jews who resisted the Nazi occupation.

At the monument he briefly made a sign of blessing to more than 40 elderly Poles who risked their lives helping Jews during the war.

Flag-waving crowds lined the 10-kilometre (six-mile) route from the airport.

The pontiff later held a special service for Polish clergy at the cathedral.

He will celebrate Mass in Warsaw on Friday, when more than a million people are expected in Pilsudski Square.

Priority pilgrimage

Polish President Lech Kaczynski and Cardinal Primate Jozef Glemp were among the dignitaries who welcomed the Pope at the airport.

The Auschwitz visit is part of Vatican efforts to reach out to Jews

"This is not just a sentimental journey, but a journey of faith," the Pope said on arrival.

"I am happy to be here, among you, on the soil of the Polish republic. I so wanted to visit the country of my beloved predecessor."

President Kaczynski said "providence has deemed that a German has succeeded a Pole on the throne of Saint Peter".

"Our two peoples, who are very close, have often been separated by history," he told the pontiff.

Poles are unlikely to have the same emotional connection with the new Pope - but as a trusted aide and close friend of John Paul he is the next best thing, the BBC's Adam Easton reports from Warsaw.

Since his election a year ago, the Pope has been to southern Italy and to his native Germany - but the trip to Cologne had been planned by his predecessor.

"Poland is his choice, the first trip he scheduled," the Polish ambassador to the Holy See said last week.

The Pope - who already speaks fluent French, English, Italian, Spanish and Latin - is said to have taken intensive lessons in Polish.

During the trip, the Pope is due to stop at John Paul's birthplace.

With the possible exception of Malta, Poland is still the most overtly Catholic country in Europe.

Two parties espousing traditional Catholic values share power in Poland and many Poles are regular church-goers.

That is partly because the Church was the only force which kept Polish national identity alive in the 19th Century, after foreign powers divided up the country and Poland ceased to exist, our correspondent says. The Church played a similar role under Soviet domination in the second half of the 20th Century.