Benedict's predecessor John Paul II had a led a campaign against the U.S.-led invasion of Iraq in 2003 but the president and the pontiff see eye-to-eye on many moral issues, such as abortion, gay marriage and embryonic stem cell research.
A Vatican statement said the two discussed the "defence of fundamental moral values" as well as the Middle East and a commitment to peace in the Holy Land, globalisation, and the world food crisis.
A White House spokeswoman said Bush and Benedict had "established a good relationship" enabling them to talk on a range of issues including AIDS, Africa and combating poverty.
MIDEAST DIPLOMACY
La Repubblica newspaper said not everyone in the Vatican was happy to see Benedict giving Bush special treatment. It quoted unnamed monsignors recalling that Bush did not heed the late John Paul's warnings against invading Iraq.
But one Vatican official close to the pope told Reuters early on Friday: "The pope is doing this because he is a gentleman. That's the long and short of it."
Condemned by many Europeans for the war in Iraq, Bush is seeking a diplomatic solution to a standoff with Tehran over its nuclear energy programme while also making it clear that military options remain on the table.
From the Vatican, Bush headed to the airport to leave for Paris, where he will address the Organisation for Economic Cooperation and Development and where he is expected to renew his call to prevent Tehran from obtaining a nuclear bomb and seek support for democracy in the Middle East.
To rally support for his Iran policy, Bush will see his close friend Sarkozy on Friday and Saturday, followed by a stopover in London on Sunday and Monday where he will confer with Prime Minister Gordon Brown.
"All of us need to be sending the same message to the Iranians, which is verifiably suspend your enrichment programme or else you will face further sanctions and further isolation," Bush said after meeting Italian premier Silvio Berlusconi.
In Tehran, leading cleric Ayatollah Mohammed Emami-Kashani, accused Bush and the United States of "setting the whole world on fire" with his campaign against Iran.
"What Iran is doing is merely scientific and economic work. What Iran is doing has got only industrial and peaceful purposes," he said at Friday prayers broadcast on state radio.
