Pope Francis arrived in Japan on Saturday where he is going to deliver a robust anti-nuclear message of peace is the only country to have suffered an atomic bomb attack.

Francis’s four-day trip will take in visits to Nagasaki and Hiroshima, cities forever associated with the nuclear bombs dropped on them at the end of World War II, that left at least 74,000 people dead.

In a video message to the Japanese people before he left the Vatican, Francis railed against the “immoral” use of nuclear weapons.

Francis had arrived in Thailand on Wednesday where he gave a message of peace and promote denuclearisation.

He is expected to do the same in Japan, a country with only approximately 440,000 Catholics out of a population of 126 million.

This was the 82-year-old pontiff’s 32nd international trip and his fourth trip to Asia having visited South Korea in 2014; Sri Lanka and the Philippines in 2015; and Myanmar and Bangladesh in 2017.

Francis is also expected to pay tribute to these so-called “hidden Christians” — or “kakure kirishitan” in Japanese — during his trip on Sunday to Nagasaki, where they were discovered.

Francis has met with Thai King Vajiralongkorn and also sat down with the Buddhist Supreme Patriarch — the head of Thailand’s Buddhists — readily taking off his shoes during the visit to adhere to local customs.

During a public address in Bangkok, the pontiff expressed gratitude to the small Catholic community for the warm welcome he received.

The first person to greet Francis as he got off the plane was his second cousin Ana Rosa Sivori, a 77-year-old nun who has lived in Thailand for 53 years and will act as the Pope’s translator during his stay.

On November 25, the pope will meet with ten victims of the so-called “triple catastrophe” of Fukushima that in 2011 killed 18,000 people as a result of an earthquake of magnitude 9 on the Richter scale, a tsunami and an accident at the nuclear power plant.

Pope Francis will also visit Emperor Naruhito at the Imperial Palace and will meet Prime Minister Shinzo Abe and civil and diplomatic authorities.