The call came just before the U.S. and South Korea opened a massive joint military air exercise Dec. 4.

The pope’s comments on nuclear weapons are seen as a significant change from John Paul II’s reluctant acceptance of them for their deterrent value.

In the past, Francis has strongly condemned the "persecution of our Rohingya brothers," denounced their suffering because of their faith and called for them to receive "full rights."

Many readers also pointed out that in comparison with other foreign policy issues, climate change’s consequences are the broadest and have the most impact.

The United States last year called Islamic State's atrocities in the region constituted genocide.

Although he named no countries, Vatican observers believe he is referring especially to political leaders in several western and eastern European countries.