Pope Benedict has urged President George W Bush to use patient diplomacy to resolve conflicts, but did not mention the Iraq war to which the Vatican is strongly opposed.
In his speech the Pope said he came to the US as a friend and a preacher of the Gospel.
The Pope, marking his 81st birthday, was full of praise for US society, sprinkling his speech with references to the Declaration of Independence and the first president, George Washington.
But he made no specific references to issues such as abortion and the war in Iraq, appearing at pains to avoid saying anything that could be seen as taking sides in the presidential campaign apart from saying that freedom called for reasoned public debate.
The Pope and Mr Bush both oppose abortion and embryonic stem cell research, but differ on questions such as the Iraq war and capital punishment.
Instead, the pope concentrated on US religious roots, which he said were a driving force in a process that 'forged the soul of the nation' and won the admiration of the world.
The Pope, who will be visiting New York and addressing the United Nations as part of his first trip to the US as Pope, was only the second pontiff to visit the White House and the first in nearly 30 years.
Looking forward to his speech to the UN, the Pope said the need for global solidarity is 'as urgent as ever if all people are to live in a way worthy of their dignity' and secure a place at 'that table which God's bounty has set for all his children.'
The Pope ended his speech by saying 'God bless America.'
The outdoor ceremony at the White House was attended by more than 9,000 people.
Among those who attended were first lady Laura Bush, Vice President Dick Cheney and his wife Lynne and Speaker of the US House of Representatives Nancy Pelosi.
Later today, the Pope will address US bishops at the National Shrine of the Immaculate Conception, where he was to discuss the scandal of sexual abuse of children by priests.
Last night, on his flight from Rome, the Pope told journalists he was deeply ashamed by the scandal involving paedophile priests in the US.
Speaking in English, he said the Catholic Church could not allow such people to remain in the priesthood.
He also vowed to raise the issue of immigration when he holds one-on-one talks with Mr Bush at the White House.
Hispanics make up nearly 40% of the 70m Catholics in the US and are increasingly targeted in efforts to crack down on illegal immigrants.
Benedict is also expected to raise the issue of US involvement in Iraq, where more than 4,000 US soldiers have died in a war that was strongly opposed by his predecessor, Pope John Paul II.
