Pope Francis today asked pilgrims and believers worldwide to join him in praying that the historic summit meeting between the leaders of the United States and North Korea, scheduled for June 12, “may contribute to the development of a positive path that can assure a future of peace on the Korean peninsula and throughout the entire world.”

He said he wished to extend to “the beloved Korean people a particular thought in friendship and prayer.”

He then went on to invite believers worldwide and the thousands of pilgrims gathered in St. Peter’s Square at midday, June 10, to join him in praying for the success of the first ever face-to-face meeting between a sitting president of the United States and the leader of North Korea. “Let us all together invoke Our Lady, Queen of Korea, [that] she may accompany these talks,” he said. He then led all present in reciting the Ave Maria with him for the success of the summit.

As he was speaking, the North Korean leader, Kim Jong-un, was already in Singapore, and not long after he finished speaking, President Donald Trump flew in on Air Force One. There is immense interest in the summit not only in Asia, but across the world.

The Russian president, Vladimir Putin, expressed his appreciation that the summit was taking place and praised China for the role it has played in ensuring it would happen. Some 3,000 journalists from across the globe have arrived to cover the event.

Pope Francis and Vatican diplomats have followed with growing concern the grave tensions and even threats of nuclear attacks that have been exchanged between the United States and North Korea.

Pope Francis knows well the fragile and often dramatic political reality in the Korean peninsula where the country has been divided along the 38th parallel since the end of World War II. Its people have suffered tension and conflict ever since the Korean War (1950-53), which ended with an armistice, not a peace treaty.

He visited South Korea in 2014, where there is a vibrant Catholic community with some 5.5 million members—just over 10 percent of the South Korean population. At the end of that visit, he celebrated a nationally-televised Mass on Aug. 16 in the cathedral of Myeong-dong “for the peace and reconciliation” of the entire Korean people, many of whose families have been divided across the 38th parallel ever since 1945

In his homily, in the crowded cathedral, he invited everyone to “pray for the emergence of new opportunities for dialogue, encounter and the resolution of differences, for continued generosity in providing humanitarian assistance to those in need and for an ever-greater recognition that all Koreans are brothers and sisters, members of one family, one people. They speak the same language.”

Pope Francis and Vatican diplomats have followed with growing concern the grave tensions and even threats of nuclear attacks that have been exchanged between the United States and North Korea, a country of 25 million people with few Catholics, over the past year because of the North Korea’s effort to develop nuclear arms. He has watched the escalation of tensions between the two sides especially over the past 12 months or more, with bellicose verbal exchanges between Mr. Trump and Mr. Kim.

His decision last year to condemn even “the possession” of nuclear arms as “immoral” also resulted from this dramatic situation where the terrifying prospect of the use of nuclear weapons, even by accident, became every day more threatening to the peoples of Korea and the United States, but also to the wider world.

Sources say Pope Francis is praying that the historic summit can open the path to the denuclearization of the peninsula, and a permanent peace agreement between the two Koreas.

Gerard O’Connell is America’s senior Vatican correspondent and author of The Election of Pope Francis: An Inside Story of the Conclave That Changed History. He has been covering the Vatican since 1985.