Stricter United Nations rules to prevent nuclear materials from falling into the hands of terrorists will go into effect next month, the International Atomic Energy Agency announced on April 8.
Ten countries including Pakistan, Azerbaijan, and Kuwait signed an amendment to the Convention on the Physical Protection of Nuclear Material last week, and Nicaragua's signature on April 8 pushed the treaty past the threshold of 102 signatories needed to trigger its entry into force in a month's time.
North Korea and Iran are among the few nuclear countries that have neither adopted the original 1987 convention nor the updated version.
Previously, the treaty was aimed at making sure that uranium or plutonium does not become accessible to violent extremists during transportation from one country to another.
The amendment obliges governments to also protect nuclear installations and materials within countries.
The advances of Islamic State militants in the Syrian war and recent attacks in Europe have heightened international concern that terrorists could try to obtain radioactive materials or attack nuclear power plants.
The updated convention broadens the list of punishable criminal acts, by including smuggling of nuclear materials, sabotaging nuclear installations, and creating environmental hazards.