VATICAN CITY - THE White House says it expects 'frank' but constructive talks in President Barack Obama's meeting on Friday with Pope Benedict XVI - two men who share similar views on helping the poor and pushing for Middle East peace but disagree on abortion and stem cell research.

With some Catholic activists and American bishops outspoken in their criticism of President Obama, even as polls have shown he received a majority of Catholic votes, the audience is much awaited.

President Obama's election presented a challenge for the Vatican after eight years of common ground with President George W. Bush in opposing abortion, an issue that drew them together despite the Vatican's opposition to the war in Iraq.

But the Vatican has been openly interested in President Obama's views and scheduled an unusual afternoon meeting to accommodate the American president at the end of his stay in Italy for a G-8 summit meeting in the earthquake-stricken city of L'Aquila and just before he leaves for Ghana.

In the tradition-conscious Vatican, most such meetings are held at midday. The Vatican has also arranged live TV coverage of the open session of the meeting after their private talks.

Tensions grew when President Obama was invited to receive an honorary degree at the leading US Catholic university, Notre Dame. Dozens of US bishops denounced the university and the local bishop boycotted the ceremony.

Former St Louis Archbishop Raymond Burke, who now heads a Vatican tribunal, accused President Obama of pursuing anti-life and anti-family agendas. He called it a 'scandal' that Notre Dame had invited him to speak.

L'Osservatore Romano, the Vatican's daily newspaper concluded that President Obama was looking for some common ground with his speech, noting he asked Americans to work together to reduce the number of abortions.

President Obama will first hold a brief meeting with Cardinal Tarcisio Bertone, the Vatican's secretary of state, before his audience with Benedict in the pope's study.

Vatican officials said Michelle President Obama and their two daughters are expected at the Vatican before the president arrives from L'Aquila for a tour of St. Peter's Basilica and the Sistine Chapel. They then will join President Obama to meet the pope at the end of the private talks. -- AP