The UN chief made the appeal in his message for the International Day Against Nuclear Tests, observed on Sunday, 29 August.

The date marks the 30th anniversary of the closure of the Semipalatinsk nuclear test site in Kazakhstan, the largest of its kind in the former Soviet Union, where more than 450 nuclear devices were exploded over four decades.

Terrible consequences

Mr. Guterres said nuclear tests caused enormous human suffering and environmental damage.

“They had terrible consequences on the health of people living in affected areas.  Many were relocated from their ancestral lands, disrupting their lives and livelihoods.  Pristine environments and ecosystems were destroyed, which will take decades, if not centuries, to heal.”

The closure of the Semipalatinsk test site signaled the end of the era of unrestrained nuclear testing, said Mr. Guterres.  Soon afterwards, countries began negotiating the CTBT.

The treaty bans all explosive nuclear weapons tests anywhere, by any country, he added, effectively “putting a brake on the nuclear arms race and providing a powerful barrier to the development of new nuclear weapons.”

No excuse

The CTBT was adopted in 1996 and has been signed by 185 countries, and ratified by 170, including three nuclear weapon States.  However, it must be signed and ratified by 44 specific nuclear technology holder countries before it can enter into force.

Even though the world has witnessed the gradual development of a norm against nuclear testing in the three decades since the closure of the Semipalatinsk site, Mr. Guterres lamented that the full potential of the CTBT has not been realized.

Despite its near universal acceptance by countries, it has yet to enter into force.

“I once again urge those states that have not yet ratified the treaty to do so without delay.  Eight States whose ratifications are necessary for the Treaty to enter into force have a special responsibility.  At the same time, all States should maintain or implement moratoria on nuclear explosions,” he said.

“The International Day Against Nuclear Tests is an opportunity to reaffirm our commitment to outlaw all nuclear tests, by anyone, anywhere.  There is no excuse to delay achieving this goal.”