President George Bush and his wife Laura, as well as other senior state officials greeted the pontiff, who turned 81 today, with over 9,000 invited guests attending the welcoming ceremony.
During the tour, Benedict XVI is expected to visit the United Nations headquarters in New York, and lead prayers at Ground Zero, the site of the September 11, 2001 terrorist attacks.
The pope and Bush are likely to discuss problems faced by Christians in Iraq and the Holy See's stance on same-sex marriage and abortion.
In a speech before the UN General Assembly on April 18, Benedict will touch upon human rights and traditional family values.
Bush already met the pope during a visit to the Vatican last June.
The reputation of the Catholic Church in the United States has been marred by a sex scandal which first emerged in 2002 and to date has involved 5000 reported sexual abuse cases of children by Catholic priests. The Vatican has paid out over $2 billion in compensation settlements to victims.