Anti-war activists and hundreds of other demonstrators marched through the Italian capital on Wednesday as Mr. Bush arrived for a visit that was to include meetings with Berlusconi on Thursday and Pope Benedict XVI on Friday.
The American president encountered scant signs of protest on his motorcade route Thursday.
At the elegant hillside Villa Aurelia, part of the American Academy in Rome, Mr. Bush met with young Italian entrepreneurs who receive training in the United States through an exchange program. He encouraged them to come get the "firsthand truth about America" and disputed what he called misinformation and propaganda about the United States.
"We are compassionate, we are an open country, we care about people, we are entrepreneurial," Mr. Bush said. "We love the entrepreneurial spirit."
A short time later, Mr. Bush was greeted by Italian President Georgio Napolitano at Quirinale Palace, situated atop the highest hill in Rome. Originally built as a summer home for popes at the end of the 16th century, the palace is now the official residence of the president.
Security is extremely tight for Mr. Bush's two-day stay in the Italian capital. Commercial flights have been banned over the city. Dozens of buses and trams have been rerouted. Thousands of policemen have been deployed as part of a plan to monitor any further protests, though Wednesday's march drew far fewer demonstrators than previous visits by Mr. Bush.
Slovenia and Germany, the first two stops on Mr. Bush's trip, were devoid of demonstrators. One activist group in Germany that had organized protests during previous Mr. Bush visits explained that they did not think this trip was important enough because he has little time left in office.
The Rome protest, though smaller than past demonstrations, was evidence that the Italian public still opposes the Bush administration.
Unlike other European leaders, such as former German Chancellor Gerhard Schroeder and former French President Jacques Chirac, Berlusconi supported Mr. Bush on Iraq from the start. The 71-year-old media mogul defied domestic opposition and dispatched about 3,000 troops to Iraq after the fall of Iraqi President Saddam Hussein.
Those troops came home, and Berlusconi, recently elected to his third stint in power since 1994, has pledged not to send any back.
More than 2,000 Italian troops, however, are deployed as part of the NATO-led mission in Afghanistan.
Italy, along with Germany, France and Spain, have restricted their troops to less dangerous areas in northern Afghanistan. That has caused a rift because other NATO members are deployed in the more violent regions of the nation. The Italian government is reviewing the restrictions and Berlusconi's office said the premier would talk to Mr. Bush about that when they meet.
Mr. Bush's wife, first lady Laura Bush, on Wednesday pledged $10.2 billion on behalf of the United States to Afghanistan's reconstruction. She spoke at an international donors conference in Paris, where the president himself will be headed on Friday.
Berlusconi and Mr. Bush also were expected to discuss Italy's interest in joining with the five permanent members of the U.N. Security Council plus Germany that are making a diplomatic push to get Iran to give up what the West believes is an effort to develop nuclear weapons. That might seem unusual for Italy, which recently surpassed Germany as Iran's largest trading partner.
But to show Italy's strong opposition to Iran's suspected nuclear ambitions, Berlusconi and his government refused to meet with Iranian President Mahmoud Ahmadinejad, who was in Rome for a U.N.-sponsored food summit last week.
Mr. Bush will meet with the pope on Friday before departing to Paris to continue his farewell European tour. It will be Mr. Bush's third meeting with Benedict. The two last met in April at the White House in Washington.
Meanwhile, in a speech Friday in Paris, Mr. Bush will urge Europe to work with the United States on matters that extend beyond their trans-Atlantic ties, such as securing Mideast peace, curtailing the rise of radical Islamic terrorists and keeping regimes such as Iran in check.
"Instead of dwelling on our differences, we are increasingly united in our interests and ideals," Mr. Bush is expected to say. "In leaders like Berlusconi and Brown, Merkel and Sarkozy, I see a commitment to a powerful and purposeful Europe that advances the values of liberty within its borders, and beyond."
The White House released a portion of Mr. Bush's remarks on Thursday, while the president was still in Rome.