United Nations Secretary General Ban Ki-Moon called Monday on all UN members to ratify a resolution banning the testing of nuclear weapons.
A total of 154 UN member states out of 195 ratified the Comprehensive Nuclear Test Ban Treaty in 1996. The United States, China, Pakistan, India, Israel and North Korea are among those countries which have yet to ratify it.
"Current voluntary moratoriums on nuclear weapon tests are valuable, yet they are no substitute for a global ban," Ban said in a speech marking the International Day against Nuclear Tests.
The UN established an International Day against Nuclear Tests in 2009 on the 20th anniversary of the closure of the Semipalatinsk nuclear test site in Kazakhstan.