Leonardo DiCaprio honoured the life and legacy of late Pope Francis, who died at 88 on April 21.

The Titanic star, who met with the religious personality in 2016, for his documentary Before the Flood, shared pictures from that meeting on Instagram.

“Pope Francis was a transformational leader not only for Catholic Church, but also for environmental reform and activism,” wrote The Wolf of Wall Street actor in the caption.

Referring to a 2015 letter on climate change that Francis sent to churches around the world, the actor called him out for his “deep and unwavering commitment to environmental stewardship.”

Talking about the document, DiCaprio said that through it Francis “helped catalyse momentum ahead of the global 2015 COP21 conference.”

The Oscar winner went on to share his experience of meeting the deceased for a “conversation on the urgent need to address climate change,” as a research for his documentary.

He penned, “That experience was enlightening, deeply moving and thought provoking.”

“His legacy will continue to inspire generations of environmentalists around the world. May he rest in peace,” DiCaprio concluded.

DiCaprio highlighted his meeting with the Francis in Before the Flood to denote that a Catholic Pope had accepted the scientific theories behind the climate crisis for the first time.

The Leader of Roman Catholic Church, Francis died of a stroke and subsequent heart failure, according to the Vatican.