Pope Leo on Wednesday appealed to the leaders of Russia and the United States to renew the New START treaty, the last remaining agreement limiting the deployment of strategic nuclear weapons.

During his weekly audience at the Vatican, Pope Leo urged Washington and Moscow to take immediate steps to extend the New START nuclear arms control treaty.

The pope said the current global situation demands every possible effort to prevent a renewed arms race and growing instability.

Warning against new arms race

Pope Leo stressed that the world stands at a critical moment as the treaty nears its expiration.

“This moment calls for doing everything possible to avert a new arms race,” he said, highlighting the moral responsibility of global powers.

The New START treaty, signed in 2010, limits the number of strategic nuclear weapons deployed by both countries.

It is set to expire on Thursday, raising concerns among arms control advocates about the absence of any binding restrictions afterward.

Positions of Russia and US

Russian President Vladimir Putin proposed in September that the treaty could be informally extended for another year.

However, as of Wednesday, US President Donald Trump had not responded to the proposal.

Pope Leo issued what he described as an “urgent appeal” to prevent the treaty from lapsing.

He said it was essential to move away from fear and distrust and toward a shared ethical approach that prioritizes the common good.

If New START expires, it would mark the end of more than 50 years of formal constraints on nuclear weapons between major world powers.

Analysts warn that this could significantly alter the global security landscape.