VATICAN CITY (CNS) — Pope Francis will meet with young people, the marginalized, government officials, bishops, priests, religious and missionaries, when he travels to Indonesia, Papua New Guinea, Timor-Leste and Singapore in September.

The 12-day Asian tour will be the longest trip of his papacy. He intends to visit: Jakarta, the Indonesian capital, September 3-6; Port Moresby and Vanimo, Papua New Guinea, September 6-9; Dili, the capital of Timor-Leste, September 9-11; and Singapore September 11-13.

The focus of the visit will be encounters with people on the peripheries. He will meet with the elderly, the ill, “street children,” the disabled and all those who minister to them, as well as leaders of government and civil society.

He will hold meetings with local Catholics and his fellow Jesuits and celebrate Masses in all four countries. When he visits the predominantly Muslim nation of Indonesia, he will have an interreligious meeting at the Istiqlal Mosque in Jakarta. He will also hold an interreligious meeting with young people in Singapore, which, according to an analysis by the Pew Research Center in 2014, appears to be the world’s most religiously diverse nation.

With 281.5 million people, Indonesia has the world’s fourth-largest population and is the world’s most populous Muslim nation, according to the CIA’s World Factbook. About 87.4% are Muslim, 7.5% are Protestant, 3.1% are Catholic and 1.7% are Hindu.

The island nation of Papua New Guinea in Oceania is: a member of the British Commonwealth of Nations, the world’s third largest island country and home to at least 10 million people. It is considered the most linguistically diverse country in the world with about 840 known Indigenous languages. About 70% of the population are Christian, 26% are Catholic and 1.4% belong to a non-Christian religion, according to the World Factbook.

Internationally recognized as an independent state in 2002, Timor-Leste had been under Portuguese and then Indonesian rule for decades. At least 100,000 people died during a two-decade-long “pacification” program and nearly 500,000 people were displaced by anti-independence militias before 2002.

Timor-Leste is still one of the world’s poorest nations after years of conflict and instability. Of the country’s 1.5 million people, 97.6% are Catholic, 2% are Protestant or evangelical Christian and 0.2% are Muslim.

A former British trading colony, Singapore today is one of the world’s most prosperous countries. With a population of 6 million people, 31.1% are Buddhist, 18.9% are Christian — of which 37.1% identify as Catholic, 15.6% are Muslim, 8.8% are Taoist, 5% are Hindu and 20% identify with no religion.