Pope Benedict left Rome on Tuesday on a six-day trip to the United States, during which he will pray at Ground Zero in New York, address the United Nations and try to heal wounds from a sexual abuse scandal.

His specially chartered Alitalia Boeing 777 left Rome's Fiumicino airport for Andrews Air Force Base, where he was due to be greeted by U.S. President George W. Bush.

The Pope meets Bush again at an official welcoming ceremony at the White House on Wednesday, when the pontiff turns 81.

The trip is Pope Benedict's first to the United States since he was elected pope in 2005 following the death of his more charismatic predecessor, John Paul II.

It is also the first by a pontiff since a wave of sex abuse scandals began in 2002, provoking lawsuits that have forced dioceses to pay more than $2 billion in settlements.

The Vatican has said the Pope will discuss the scandal during his visit in an effort to seek reconciliation. Meetings with sex abuse victims are not on the Pope's public schedule, but sometimes events are added at the last minute.

"The Pope will talk about it - talk about it in a specific way," Cardinal Tarcisio Bertone, Vatican Secretary of State, told a US television network ahead of his trip.

"The Pope, along with the Church's priests, will naturally seek the path toward healing and toward reconciliation."


SPIRITUA RENEWAL

A poll released this month by the Pew Forum on Religion & Public Life showed the German-born Pope was viewed favourably by most Americans, but was not as popular as John Paul was and did not share the same name recognition.

Known as a fierce conservative when he was elected, the Pope has surprised many people with his gentle manner and by underlining the positive in Catholicism rather than the negative.

But he has also made headlines with some missteps, including a 2006 lecture he delivered in Germany that was taken by Muslims to imply Islam was violent and irrational. Muslims around the world protested.

The Pope, who will also mark the third anniversary of his election during the trip, has said he hopes the visit will lead to a spiritual renewal for America's faithful.

The Pope will address the United Nations on Friday, and has said he aims to draw attention to the need for greater peace and justice around the world.

In New York, Pope Benedict will also make a brief stop at a synagogue to wish the city's Jewish community a happy Passover.

He ends the trip on Sunday after visiting Ground Zero, the site of the World Trade Center towers destroyed in the September 11, 2001 attacks on the United States. He will also say Mass at Yankee Stadium.