WASHINGTON - Pope Benedict XVI yesterday began the first full day of his visit to the United States with a welcoming reception at the White House, and later delivered a stern address to his bishops, saying they must counter the "enormous pain" of the clergy sex-abuse scandals.

Speaking at the Shrine of the Immaculate Conception, he instructed the bishops to promote wholesome moral values across all of U.S. society.

While never scolding them for concealing abuse, Benedict told the bishops that the abuse was "sometimes very badly handled" and insisted that "the vulnerable always be shielded from those who would cause harm."

By acknowledging and confronting sexual abuse in their own dioceses, the pontiff said: "You can give a lead to others, since this scourge is found not only within your diocese, but in every sector of society."

The bishops must address "the degrading manifestations and crude manipulation of sexuality so prevalent today," Benedict said, and "lead by example."

After his late-afternoon address at the shrine, the pope answered three prepared questions, each delivered by a bishop, about how they could better challenge the rise of secularism, the erosion of baptized Catholics from the practice of the faith, and the decline of vocations to religious life.

He replied, reading from a prepared text, that bishops must counter secularism and "attrition" with a better training of the Catholic laity in the fundamentals of the faith. Teaching and encouraging young people to pray deeply was essential to promoting religious vocations, he said.

The solemnity of the meeting with the bishops was in marked contrast to the buoyant - at times playful - welcome at the White House.

Grinning broadly, the pontiff greeted with outstretched arms the thousands who filled the South Lawn of the president's home, where many waved American flags and small children carried signs reading "Pope of Hope."

In his remarks, President Bush told Benedict the nation was honored he had chosen to spend his 81st birthday in America, "since birthdays are traditionally spent with close friends." He went on to assure Benedict that "here in America, you'll find a nation that welcomes the role of faith in the public square," and told him that "we need your message that all life is sacred."

In his reply, the pontiff noted that his six-day visit was in part to honor the creation 200 years ago of the Dioceses of Philadelphia, New York, Boston and Louisville, "yet I am happy to be a guest of all Americans." He said he came as a "friend, a preacher of the gospel, and one with great respect for this vast, pluralistic society."

Benedict said he hoped his visit would inspire the nation's 67 million Catholics to "contribute ever more responsibly to the life of this nation," and he urged all Americans to cultivate virtue and self-discipline, "sacrifice for the common good," and care for the less fortunate.

The welcoming ceremony included a 21-gun salute, a blaring of trumpets, a singing of the "Battle Hymn of the Republic" by soprano Kathleen Battle, and an invitation to the crowd, officially estimated at 13,500, to sing "Happy Birthday" to him, which they did.

Bush and Benedict then entered the White House, emerging briefly on the south balcony to wave to the crowd before sitting down to private talks.

A joint statement from the White House and the Vatican later characterized the talks as having touched on such matters as "the defense and promotion of life, matrimony and the family," and human rights, along with immigration, religious freedom, and "the struggle against poverty and pandemics, especially in Africa."

They also devoted "considerable time" to discussing the Middle East, according to the statement, including the Israel-Palestinian conflict and "their common concern for the situation in Iraq."

Afterward, Benedict boarded the glass-enclosed "popemobile" for the return trip to the residence of Archbishop Pietro Sambi, the papal nuncio to the United States, waving to the crowds that lined the motorcade route.

The motorcade emerged again about 5 p.m. and made its way to the Shrine of the Immaculate Conception and a vesper service that preceded his address to the bishops. Again he waved to the crowds lining the sidewalks.

Among those waving back was Billie Leeper, 54, a data programmer from Baltimore who had taken off work to watch the Holy Father go by. She called the sight of him "overwhelming" and marveled at his energy.

"He's 81 years old and he can outwalk me," she said.

Benedict was greeted at the shrine's east portico by Archbishop Donald Wuerl of the Archdiocese of Washington, who escorted him inside and pointed out some of its architectural details.

The tall, wooden chair in which the pontiff sat for the vesper service was specially commissioned by the shrine and made by St. Jude Liturgical Arts Co. of Philadelphia.

Made of American walnut and decorated with the papal coat of arms, it will be kept on display as a memento of his visit, according to Lou DiCocco, president of St. Jude Liturgical Arts.

At the close of the address to bishops, Cardinal Francis George, archbishop of Chicago and president of the United States Conference of Catholic Bishops, presented Benedict with a birthday present from the 195 dioceses of the United States: a check for $870,000 for the Vatican's charitable work.

The pope countered by presenting the shrine with a gold rose dedicated to Mary, and a chalice for the Archdiocese of New Orleans, in recognition of the suffering of its people from Hurricane Katrina.

The bishops finished with a chorus of "Happy birthday, Holy Father."

The Pope's Visit: Today's Events

10 a.m.: Pope Benedict XVI will offer Mass at the new Nationals Park baseball stadium in Washington.

5 p.m.: The pontiff will give an address on the importance of Catholic education on the campus of the Catholic University of America.

6:30 p.m.: Buddhists, Muslims, Hindus, Jews, and representatives of other religions will meet the Holy Father at the Pope John Paul II Cultural Center, next

to Catholic University.

Read White House transcript or watch video of Bush's

and Benedict's remarks via

http://go.philly.com/pope.bush