Pope Leo XIV has strongly criticised the death penalty, calling it an attack on human dignity.
His remarks came as the United States prepares for the planned execution of former Army psychiatrist Nidal Hasan, convicted over the 2009 Fort Hood shooting.
The US military has announced that Hasan is scheduled to be executed by firing squad on December 3.
The execution is expected to be livestreamed publicly, making it an unusually high-profile case in modern US military justice.
Pope Leo XIV said the death penalty cannot be justified as a legitimate response to crime.
He argued that human life retains dignity even when a person has committed serious offences.
The pontiff also urged governments and societies to reject capital punishment and focus instead on justice systems that preserve human life.
Hasan was convicted of killing 13 people and wounding more than 30 others during a mass shooting at Fort Hood in Texas.
He was sentenced to death by a military jury in 2013.
If the execution proceeds, it will be the first carried out by the US military since 1961.
The case has revived debate over capital punishment, military justice and the decision to broadcast an execution publicly.
Supporters of the death penalty argue that the punishment reflects the severity of certain crimes.
Opponents, including the Catholic Church, maintain that executions violate fundamental human dignity and do not provide true justice.
Pope Leo XIV’s comments add a prominent religious voice to the international debate.
The Catholic Church has increasingly opposed capital punishment in recent years and has called for its abolition worldwide.
As the December execution date approaches, the case is expected to attract further legal, ethical and public scrutiny.
