Pope Leo has warned that humanity's future is at risk of being "tragically compromised" because of ongoing wars and a breakdown of international law.
During a speech in Equatorial Guinea during his four-nation Africa tour, he decried what he called the "colonisation" of the Earth's oil and mineral resources, which he said is driving bloody conflicts.
He said: "The destiny of humanity risks being tragically compromised without a change of direction in the assumption of political responsibility and without respect for institutions and international agreements".
In the speech to Equatorial Guinea President Teodoro Obiang Nguema Mbasogo and other political leaders, the head of the 1.4-billion-member Church said: "God does not want this."
He added: "His holy Name must not be profaned by the will to dominate, by arrogance or by discrimination. Above all, it must never be invoked to justify choices and actions of death."
Obiang has led Equatorial Guinea since 1979 and has been widely criticised as one of the most repressive leaders in the region. His government denies allegations of human rights abuses and corruption.
The country was the last leg of Leo’s Africa tour in which he has forcefully decried the direction of global leadership, denouncing despotism and war, and drew the ire of President Trump.
Tens of thousands of people gathered to hear his final Mass in which he told worshippers that the Christian message means "every people is set free from the slavery of evil" and he urged them to live their faith with joy.
(Some reporting by Reuters)