Michele Chabin

Special for USA TODAY

BETHLEHEM, West Bank — Israeli and Palestinian leaders accepted an invitation to the Vatican next month from Pope Francis, who urged the two sides to make sacrifices to achieve peace Sunday during his first visit as pontiff to the Middle East.

"The time has come for everyone to find the courage to be generous and creative in the service of the common good," Francis said at a welcoming ceremony in Bethlehem hosted by Palestinian President Mahmoud Abbas. "The climate of instability and a lack of mutual understanding have produced insecurity, the violation of rights, isolation and the flight of entire communities, conflicts, shortages and sufferings of every sort."

A festive atmosphere greeted Francis in Bethlehem's Manger Square, the traditional birthplace of Jesus, where posters of the pope, called baba in Arabic, hung in every shop window. Riding through the crowd on his way to Mass, the pope was greeted by cheers of Viva al-Baba! or "Long live the pope!"

Two enormous flags, one the yellow and white of the Vatican, the other the red, white, black and green Palestinian flag, were draped, side by side, from a building on the square.

A large mural depicting the holy family — flanked on one side by past popes, and on the other by local saints — served as a backdrop to the stage where Francis and members of the Palestinian Catholic Church held the outdoor Mass.

At the end of the Mass, Francis invited Abbas and Israeli President Shimon Peres to Rome.

"I offer my home in the Vatican as a place for this encounter of prayer," he said. The offices of the Israeli and Palestinian presidents quickly confirmed that they had accepted the invitation. Peace talks between the two countries broke down in late April.

The pope's decision to fly by helicopter from Amman, Jordan, into Palestinian-ruled Bethlehem gained favor with Palestinians, who felt it was a small but important acknowledgment of their aspirations for sovereignty.

Pope John Paul II and Pope Benedict XVI, who made Holy Land pilgrimages in 2000 and 2009 respectively, each flew to Tel Aviv before visiting Bethlehem.

"It's a blessed day," said Samar Sakkakini, 52, a Palestinian American from Canton, Mich., who attended the Mass in Manger Square. "Coming to Bethlehem and flying to Bethlehem from Jordan shows solidarity with the Palestinian people, which is wonderful. We need that."

Many of the pilgrims traveled to Bethlehem from Israel for the Mass. Although the Israeli government prohibits Israelis from entering Palestinian-ruled areas in the West Bank, the Christians received special travel permits.

"We wanted to see the pope," said Gracy Cunha, who works in Israel as a caregiver. Cunha, who is from India, and a large group of Indian foreign workers who attend her church, said the group left Haifa, a city in northern Israel, at 2 a.m. in order to pass through the Israeli checkpoint into Bethlehem as well as Palestinian security.

"This is a special opportunity for us, a once-in-a-lifetime opportunity," she said.

Over the decades, hundreds of thousands of Palestinians, including large numbers of Christians, have emigrated because of wars, uprisings and subsequent financial instability. Today, Christians comprise just 2% of the population of the Holy Land.

In an unscheduled visit earlier Sunday, Francis stopped briefly to pray at the tall separation wall Israel built several years ago to prevent Palestinian terrorists from entering Israel. The wall, which is covered with calls for Palestinian statehood and tributes to Palestinians imprisoned in Israeli jails, severely restricts Palestinians' ability to visit Israel.

Additional stops on the pope's itinerary also had political overtones, including a visit to a refugee camp to meet Christian and Muslim children whose ancestors were displaced from their homes during wars with Israel and a lunch with Palestinian families whose land was confiscated by Israel or whose sons are imprisoned in Israel, according to the Latin Patriarchate.

Palestinians, meanwhile, were gratified the Vatican's official program on the pilgrimage called Abbas the president of the "state of Palestine," a phrase that appeared on the T-shirts the Bethlehem municipality handed out at the entrance to Manger Square, along with Palestinian flags.

In his remarks, Abbas voiced concerns about the breakdown in peace talks, but also expressed hope on the pontiff's visit. "Your visit is loaded with symbolic meaning as a defender of the poor and the marginalized," he said.

Security was lax by papal standards, even for a pope who has shunned the armored popemobile that his predecessors used on foreign trips. Only two bodyguards stood on the back of Francis' vehicle keeping watch as Palestinian police kept the crowd at bay. Francis waved and warmly smiled as his car made its way through the crowd in Manger Square, at one point holding a child passed up to him.

Standing behind a table loaded high with free mineral water bottles, 17-year-old Vicky Handal, a Palestinian Catholic from Bethlehem, said she was excited to see Pope Francis in person. Still, she wasn't completely at ease with the atmosphere surrounding the pontiff's visit.

"I don't like the fact that political leaders on both sides are politicizing the pope's visit," she said. "The primary focus of the pilgrimage must be unity among Christians, not politics."

Contributing: The Associated Press