VATICAN CITY— (UPDATE) US President Barack Obama on Friday promised to try to reduce abortions in his country during his first meeting with Pope Benedict XVI, while also discussing Middle East peace efforts.

Visiting the pope after this week's G8 summit in Italy, the two touched on an issue that deeply divides the US public and has set pro-abortion rights Democrats like the president at odds with Vatican policy.

"The pontiff told me that President Obama affirmed his personal commitment to try to reduce the number of abortions in the United States," Vatican spokesman Federico Lombardi told reporters.

In talks that lasted about 40 minutes, the US president and the head of the Roman Catholic Church also discussed Obama's efforts to reach out to the Muslim world, immigration reforms and sensitive bioethics issues.

Obama urged Benedict to keep reminding all parties to the Middle East peace efforts of their "responsibilities", the White House said.

He underlined his commitment to ending the Arab-Israeli conflict and "expressed appreciation for the longstanding efforts of the Holy See and the pope himself in promoting that," Deputy US National Security Adviser Denis McDonough told reporters.

The US president told the pope that "all sides have responsibilities in this effort" and vowed to continue delivering that message, McDonough said aboard Obama's official Air Force One airplane as he traveled to Ghana.

He also "expressed his hope that the Holy Father would continue to do that as well, including responsibilities that we believe are important, not just from Israelis but also from the neighboring Arab states," said McDonough.

Obama has made relaunching the Middle East peace process a top priority, pledging a new beginning for Islam and the United States in a landmark speech to the world's Muslims delivered in Cairo early last month.

The Vatican called this a "significant" step toward better ties.

The two men apparently did not shy away from difficult subjects, also addressing bioethics in addition to abortion.

After taking office in January, Obama ended his predecessor George W. Bush's restrictions on government funding for embryonic stem cell research and for family planning groups that carry out or facilitate abortions overseas.

As the pope offered a copy of an "instruction" on bioethical issues during the traditional exchange of gifts after their meeting, Obama said: "That's what we discussed earlier."

The US leader then quipped: "I'll have some reading to do on the flight."

Benedict, the 82-year-old head of the world's 1.1 billion Catholics, also offered the US leader a mosaic depicting St Peter's Square with one of its fountains in the foreground.

"We'll find a place of honor for that," said Obama, 47.

Obama, who attended the three-day summit of the Group of Eight that ended Friday in nearby L'Aquila, offered the pope a stole that had covered the remains of St John Neuman, a 19th-century missionary who was the first American bishop to be canonized.

First Lady Michelle Obama joined them for the traditional exchange of gifts, and Obama introduced his daughters Sasha and Malia, as well as his mother-in-law Marian Robinson, to the pope, the Vatican press office said.

As the presidential couple left, the pope said: "I'll pray for you. I'll pray for your work."

White House spokesman Robert Gibbs said earlier that on subjects such as abortion, "even if we don't see eye to eye on everything, there are steps that can be taken on a number of issues that will show progress, whether it's on something like unintended pregnancy or adoption".

Vatican expert John Allen said after the meeting that "it's obvious the pope wanted to deliver a pro-life message".

Obama gave a controversial commencement address in May at one of the top Catholic universities in the United States, Notre Dame, while hundreds of activists outside denounced his support for abortion rights.