VATICAN CITY (AP) — 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.