ROME - On what is probably his last trip as defense secretary, Leon Panetta had an audience on Wednesday at the Vatican with Pope Benedict, who told him, Panetta said, "Thank you for helping to protect the world." Panetta said he replied, "Pray for me."

Panetta, who attends mass every Sunday and is the son of Italian immigrants, is halfway through a weeklong trip to Europe meant as a goodbye tour of U.S. allies. Later Wednesday, he met with the Italian prime minister, Mario Monti, as well as the president of Italy, Giorgio Napolitano.

Panetta's audience with the pope was far from private, although he had a close-up view. Panetta sat in the front row of the Pope Pius VI Audience Hall, where 7,000 others had gathered for the pope's weekly audience. After an hourlong service, Panetta filed up with several dozen people to receive a blessing from the pope.

Defense officials said Panetta previously had an audience with Pope John Paul II when Panetta, who was a budget director and a chief of staff to President Bill Clinton, accompanied Clinton to Rome. He also had an audience with John Paul in Washington.

Panetta's likely successor is Chuck Hagel, who is preparing for Senate confirmation hearings later this month or early next month. After 18 months as defense secretary and many decades in government, Panetta plans to return to his walnut farm in Carmel Valley, Calif.

He has also visited Spain and Portugal during this trip. On Tuesday in Lisbon, Panetta restated the administration position that the United States would not send ground troops to Mali, where militants were pushing toward one of Mali's largest cities.