Pope Francis headed to Romania on Friday, May 31, with a message of integration not just for its faith communities but for a post-election European Union, following nationalist gains.

During the 3-day trip to the mainly Orthodox country, which sits at the crossroads of Western and Eastern Europe, Francis is expected to touch on issues fuelling nationalism, such as poverty, as well as inter-religious relations.

"I come to you to walk together," Francis said in a message to the people of Romania ahead of his departure.

"We walk together when we learn to keep the roots of the family, when we cater to the future of our children and of our brothers next to us, when we go beyond fear and suspicion, when we let the walls that divide us from others fall," he said.

The pontiff set off from Rome's Fiumicino airport at 0615 GMT after meeting a group of 15 homeless Romanians who live in Rome.

Relations between the Orthodox Church and Romania's Greek Catholics -- who number just 150,000 -- have been strained ever since the country was under post-war Communist rule.

The tiny community had its property confiscated while its religious leaders were jailed.

But the Greek Catholics resisted, holding secret masses until the dictatorship fell in 1989.

The pope will beatify seven bishops who were tortured and died in prison, setting them on the path to sainthood.

Golden rose

Francis's visit follows 20 years after John Paul II received a hearty welcome for his perceived role in the fall of Communism.

The Argentine pontiff will travel across the country, from Bucharest to Iasi and Blaj, to meet people of diverse faiths and languages among Romania's 20 million inhabitants -- which include 18 officially recognised minorities.

The highlight of the trip is set to be Saturday's mass at the Sumuleu Ciuc shrine in a predominantly ethnic-Hungarian part of the picturesque Transylvania region.

Tens of thousands are expected to attend the ceremony, which will see Francis present a golden rose at the large wooden replica of the Madonna -- a tradition for popes visiting major Marian shrines.

On arriving Friday in Bucharest Francis will meet president Klaus Iohannis as well as Romania's first female prime minister, Viorica Dancila, before addressing the nation in a televised speech.

The 82-year-old is expected to touch on unemployment and poverty -- factors that have driven some 16 percent of the population, mostly youngsters, to emigrate to other EU countries since Romania joined the bloc in 2007.

He will likely reference the conservative and anti-immigrant narratives that propelled many nationalist parties -- including in neighbouring Hungary -- to significant wins in last week's European parliament elections.

'Hearts and minds open'

It will be an opportunity "to send a message to the many Catholic Hungarians there to keep their hearts, minds and gates open to others," religious expert Claire Giangrave wrote in the religious news website Cruxnow.

Vatican spokesman Alessandro Gisotti said the pope's trip "will take into account" the EU populist gains.

Francis will take a turn in his popemobile through the streets of Bucharest to Saint Joseph's Cathedral where 30,000 people are expected to gather for a mass.

He will have a private meeting with Orthodox Patriarch Daniel, but while they will pray alongside each other -- one in Latin and the other in Romanian -- the pair will not appear together in public, a sign of their frosty relations.

"The challenge for the pope is to stress to the Orthodox community that the Church of Rome does not want to 'Latinize' it," said Bishop Pascal Gollnisch, director of the Oeuvre d'Orient French charity, which supports Eastern Churches.