Vatican City. Pope Francis will visit Indonesia, East Timor, Papua New Guinea and Singapore in September, the Vatican announced Friday, confirming the longest trip of Francis’ papacy that is sure to test his health, stamina and mobility.

The Vatican confirmed the Sept. 2-13 visit, saying the 87-year-old pope would visit Jakarta, Indonesia; Port Moresby and Vanimo, Papua New Guinea; Dili, East Timor; and Singapore. Further details will be announced later.

Francis' health has become a source of increasing concern and speculation, even though the pontiff is able to carry on with a rigorous schedule of meetings at the Vatican and even excursions to local parishes.

Francis, who had part of one lung removed as a young man, had to cancel a planned visit to Dubai late last year after he came down with a bad case of bronchitis. He suffered from respiratory problems all winter and had to curtail his participation in Holy Week events to save his energy for Easter.

Francis has also been using a wheelchair for nearly two years because of bad knee ligaments and has said that traveling has become increasingly more difficult.

And yet at 11 days, the trip would be the longest of Francis’ papacy, outpacing by a few days some of his long trips to the Americas early on in his 11-year papacy. It will bring the Argentine Jesuit to the world’s most populous Muslim nation, Indonesia, as well as the former Portuguese colony of East Timor, where the Catholic Church wields enormous influence.

There is also a chance of another leg to the trip being added later: This week, the Vatican foreign minister, Archbishop Paul Gallagher, was in Vietnam and discussed a papal visit, Vatican News reported, without providing details.

In a statement announcing the visit, the Indonesian foreign ministry welcomed the visit and recalled that it had originally been scheduled for 2020 but was postponed because of the Covid-19 pandemic.

“The visit of Pope Francis to Indonesia holds significant importance to the Indonesian people, not only for Catholics but also for all religious communities. The visit is also expected to strengthen the message of tolerance, unity and world peace,” the statement said.

Indonesia is home to roughly 242 million Muslims and 29 million Christians -- 8.5 million of whom are Catholics -- according to a 2022 report by the Religious Affairs Ministry.

East Timor, which today has a population of about 1.2 million people, is Southeast Asia’s only predominantly Christian nation with the exception of the Philippines. According to the 2015 census, 97.6 percent of East Timor’s population is Catholic.

The visit to East Timor will likely reignite attention over a clergy sex abuse scandal involving its revered independence hero and Nobel Peace Prize winner. The Vatican confirmed in 2022 that it had sanctioned Bishop Carlos Ximenes Belo following allegations that he sexually abused boys there during the 1990s. Belo is believed to now be living in Portugal.

Francis will be the first pope to visit Papua New Guinea since St. John Paul II went there in 1984. The country, in a strategically important part of the South Pacific, has struggled with tribal violence and civil unrest.

John Paul also visited Singapore, in 1986. The country today is home to 395,000 Catholics and Francis in 2022 made its archbishop Singapore's first cardinal.

In a statement welcoming the visit, Cardinal William Goh, said it “will bring renewed fervor to all Catholics in Singapore, uniting them in faith and mission, especially in these most challenging of times.”

The Vatican has planned only one other papal trip this year -- to Belgium to celebrate the anniversary of the country’s Catholic university. Francis has also said he wants to return to his native Argentina, but no plans or dates have been announced.