Pope Francis is presiding over a peace meeting in Bulgaria with members of the Balkan country's different faith communities and a children's choir singing "We Are the World."
There were no immediate signs at the meeting of a high-ranking representative of the Bulgarian Orthodox Church.
The Bulgarian church said it would not participate in any papal events during Francis' two-day trip, though members of its governing body greeted Francis upon his arrival Sunday.
The Monday afternoon peace meeting opened with the children's choir singing "We Are the World" in English. The 1985 song by Michael Jackson and Lionel Ritchie was recorded to raise funds for African famine victims.
Francis is traveling to North Macedonia on Tuesday. .
Not all Bulgarians are happy with Pope Francis' visit.
One of the members of the Bulgarian Orthodox Church's governing body, Metropolitan Nikolay of Plovdiv, Bulgaria's second biggest city, has called Francis' visit an "an attack against Orthodoxy."
Nikolay is known for his hard-line views. He was quoted by the website podtepeto.com as saying: "The visit by the Pope of Rome is a political act, the goal is to unite all the churches around Rome, and when the Antichrist comes, for the Pope to meet him."
Speaking at a congregation in Plovdiv on Sunday, Nikolay said: "We met the Pope of Rome as head of state of the Vatican state, but no one can force us regarding common worship with him."
"We will not give up Orthodoxy. We did not give up Orthodoxy in the five centuries of slavery," he said, referring to the period when Bulgaria was under Ottoman rule.
Pope Francis is pressing his message in Bulgaria about the need to accept migrants, saying they are all children of God and deserve love.
Francis told members of Bulgaria's Catholic community that they shouldn't pin labels on people based on their religious or ethnic background.
He said the faithful should try to "create conditions in which every person can feel loved, especially those who feel forgotten by God because they are forgotten by their brothers and sisters."
Francis was speaking in the Catholic stronghold of Rakovsky.
Pope Francis is ministering to Bulgaria's young Catholics, travelling to the Catholic stronghold of Rakovsky for a First Communion Mass and meeting with the local community.
Nearly 250 jittery children in white robes filled the pews of the Sacred Heart church Monday, the girls wearing crowns of white roses. Citing local organizers, the Vatican said some 10,000 people were on hand outside to greet Francis.
In his homily, Francis told the children that receiving their First Communion was a celebration of communion with the whole church, and he urged them to share that joy with others.
Later, he engaged in a Q&A session with the kids, explaining to them the basics of the sacrament and living a Christian life in Italian that was then translated into Bulgarian.
Pope Francis has met with refugees in Bulgaria's showcase refugee center and told them they are bearing the "cross of humanity," after he urged the migrant-skeptic government to not close its eyes to their suffering during a visit to the Balkan nation.
Refugee children from Iraq, Pakistan and elsewhere sang for Francis on Monday at the Vrazhdebna center, located in a refurbished school on the outskirts of Sofia, the Bulgarian capital.
Bulgaria's center-right government has been criticized by human rights groups and the European Council for its treatment of asylum-seekers, particularly unaccompanied minors.
Francis is on the second-day of a three-day visit to the Balkans. Later Monday, he is to celebrate Mass in the Catholic stronghold of Rakovsky and celebrate First Communion for more than 200 children.