The trip came just after President Barack Obama asked the vice president to oversee the U.S. departure from Iraq and Washington's effort to promote political reconciliation in the country.
The White House said Biden, who landed late on Thursday, was also set to visit American troops now stationed on the outskirts of Iraqi cities, following a major pullback from urban centers that was completed on Tuesday.
It also said talks with political leaders, including Prime Minister Nouri al-Maliki, renewed the U.S. commitment to complete the terms of the bilateral accord signed last November that set a timeline for the U.S. military exit.
It is Biden's first trip to Iraq since he was sworn in as vice president in January, but he previously made several trips when he was chairman of the Senate foreign relations committee.
"The vice president has been asked by the president to oversee the policy," White House spokesman Robert Gibbs said on the day of the U.S. troop pullback. Biden was expected to work with Iraqis "toward overcoming their political differences and achieving the type of reconciliation that we all understand has yet to fully take place but needs to take place," he said.
But Gibbs said an idea once put forward by Biden - dividing Iraq's Shiite, Sunni and Kurdish communities into a federation of autonomous zones - was not on the table for the Obama administration. The vice president's arrival in Baghdad was welcomed by Wathad Shaqir, chief of the Iraqi parliament's national reconciliation committee. "I believe he has brought some suggestions regarding the reconciliation project," Shaqir told state television, noting he was happy that Biden's divisional zoning idea had been abandoned. "We are looking forward to a new page."
A key problem facing the reconciliation effort is a Sunni demand that Baathists loyal to now executed dictator Saddam Hussein, who were excluded from politics after the 2003 U.S.-led invasion, be reintegrated.
Major difficulties are also posed by the crucial oil-hub city and province of Kirkuk, which Iraq's autonomous Kurdish region has laid claim to in a new draft constitution that has irked the federal government in Baghdad. The Kurds have long striven to expand their northern territory beyond its current three provinces to other areas.