Benedict departed for Washington on Tuesday, with President Bush planning to make the unusual gesture of greeting him when his special Alitalia jetliner touches down at Andrews Air Force Base - the first time the president has greeted a foreign leader there.
Planners have kept that as Benedict's only public appearance on first day of six in America, clearly trying to help him get over any jet lag. He will turn 81 on Wednesday, although he seems spry and aides pronounce him in good health.
A visit by the leader of the world's 1 billion Catholics is clearly a big deal, despite the American tradition of separation of church and state.
, larger than the gathering for Queen Elizabeth II, is expected Wednesday at the White House for the pope's official visit to the American president. The White House is also planning a gala dinner that evening - although Benedict won't be there. The White House says he will be attending a prayer service with American bishops, although it would also be unusual for a pope to attend a state dinner.
Answering reporters' questions as he was flying from Rome to Washington to begin his papal pilgrimage, the pope said he was "deeply ashamed" of the clergy sexual abuse scandal that stained the Catholic church. He pledged to work to make sure that such abuse won't happen again and that pedophiles don't become priests.
While the pope and Mr. Bush differ on such major issues on the Iraq war, capital punishment and the U.S. embargo against Cuba, they do find common ground in opposing abortion, gay marriage and stem cell research.
In his regular Sunday greeting from his apartment overlooking St. Peter's Square, Benedict asked for prayers so that his visit would be a "time of spiritual renewal for Americans."
Part of Benedict's long-term plan in the United States and abroad is to expand the church's outreach to other religions, reports CBS News correspondent Jeff Glor.
Watch the live Web cast of Pope Benedict XVI's arrival at 4 p.m. EDT
In fact, after making little headway in his efforts to rekindle the faith in his native Europe, the German-born Benedict will be visiting a country where many of the 65 million Catholics are eager to hear what he says.
A poll released Sunday by the Center for Applied Research in the Apostolate at Georgetown University found eight in 10 Catholics are somewhat or very satisfied with his leadership.
Cardinal Tarcisio Bertone, the Vatican secretary of state, said in an Associated Press interview last week that "religion is deeply rooted in American life despite the separation of church and state."
Benedict is expected to stress the importance of moral values and take on what he sees are the dangers of moral relativism - that is that there are no absolute rights and wrongs.
His address at New York's St. Patrick's Cathedral to a gathering of clergy will be watched for how he responds to the clerical sex abuse scandal that has rocked the American church. Bertone said Benedict will seek healing and reconciliation.
Also while in New York, he will deliver at major address at the United Nations. He will also visit the Park East synagogue, part of his efforts for close relations with Jews whom, like his predecessor John Paul II, he has referred to as "our older brothers in faith."
He will celebrate Mass at Nationals Park in Washington and Yankee Stadium in New York, his last major event of the trip.