Pope Leo has described those who wage wars and exploit the planet’s resources as thieves who deprive humanity of a peaceful future. Speaking on the 40th anniversary of the Chernobyl nuclear disaster, he also warned against the misuse of nuclear power. His remarks came during the Sunday Angelus prayer, as Ukraine marked four decades since the world’s worst nuclear accident amid its ongoing four-year conflict with Russia.

The Pope said the Chernobyl tragedy left a deep mark on humanity’s collective consciousness and serves as a warning about the growing power of technology. Returning from a recent visit to four African countries, he expressed hope that wisdom and responsibility would guide all levels of decision-making so that nuclear energy is used for life and peace.

Pope Leo, the first American to hold the papal office, has recently faced criticism from former U.S. President Donald Trump for his outspoken stance against war and authoritarianism.