As he arrived on a long-awaited trip to Japan on Saturday, Pope Francis issued a call for nuclear disarmament ahead of his visits to the cities of Hiroshima and Nagasaki, targets of the “catastrophic” atomic bomb.

Shortly after touching down at Tokyo’s Haneda airport, the 82-year-old Argentine turned straight to the “tragic episode in human history” at the end of World War II, which killed at least 74,000 in Nagasaki and 140,000 in Hiroshima.

“I will soon visit Nagasaki and Hiroshima, where I will offer prayers for the victims of the catastrophic bombing of these two cities, and echo your own prophetic calls for nuclear disarmament,” Francis told bishops in a welcoming ceremony.

With his four-day trip — the second leg of an Asian tour that also included Thailand — the pontiff said he was fulfilling a long-held ambition to preach in Japan.

“I don’t know if you are aware of this, but ever since I was young I have felt a fondness and affection for these lands. Many years have passed since that missionary impulse, whose realization has been long in coming,” said Francis.

The head of the world’s 1.3 billion Catholics arrived late Saturday afternoon. At the airport, the white cape of his papal outfit was whipped up by high winds as he carefully descended the plane steps in heavy rain.

Francis arrived from Thailand, where he preached a message of religious tolerance and peace.

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

The majority of Japanese practice a mixture of Shinto and Buddhism, two closely intertwined faiths based on the worship of nature and spirits, but many in Japan also observe Christian festivals such as Christmas.

Christians endured centuries of bloody repression in Japan after the religion was introduced to the country by a Spanish Jesuit priest in 1549.

In the 17th century, Japan was closed to the outside world and Christians were persecuted, forced to recant their faith, tortured, crucified and drowned.

When Japan reopened to the world in the mid-19th century and the missionaries returned, they were astonished to find an estimated 60,000 who had secretly kept the faith alive and followed a unique version of Catholicism blended with Japanese culture and religious rites.

Francis is 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 will also visit Hiroshima on Sunday and deliver remarks at the world-famous peace memorial that marks the dropping of the atomic bomb on Aug. 6, 1945.

Father Yoshio Kajiyama, director of the Jesuit social center in Tokyo, was born in Hiroshima shortly after the war and is eagerly awaiting the pope’s anti-nuclear speech.

“My grandfather died the day of the bomb in Hiroshima, I never knew him. Four days later my aunt died when she was 15 years old,” said the 64-year-old. “If you grow up in Hiroshima, you can’t forget the bomb.”

In Tokyo on Monday, Francis will meet victims of the March 11, 2011, Great East Japan Earthquake, tsunami and nuclear meltdown that devastated large swaths of the Tohoku region.