Nine years after countries agreed they were sorely needed, new global rules aimed at stopping terrorists from acquiring nuclear materials should come into force in 2014, according to a senior UN official in an article from Reuters.

An amendment to the 1980 Convention on the Physical Protection of Nuclear Material (CPPNM) was agreed in 2005, the article says, but it has not yet been ratified by two-thirds of parties to the CPPNM needed for it to come into force.

The original CPPNM covered on the international transport of nuclear material, but the amendment includes its use, storage and domestic transport, which means that international cooperation would increase in those areas, and breaking the new rules would be a crime, Reuters reports.

Fifty-nine states have already adopted the amendment, but 40 more are needed for it to come into force.

The International Atomic Energy Agency (IAEA) believes terrorist groups trying to get hold of nuclear weapons on the black market are becoming more sophisticated and more effort is needed to prevent them from getting a “dirty bomb” to contaminate a major city.

READ MORE: Authorities Team Up for Dirty Bomb Responses

The IAEA’s Illicit Trafficking Database has recorded 2,242 unauthorized incidents in 118 states since 1995, the article says. Materials used for nuclear weapons – highly enriched uranium and plutonium – accounted for 1.5 percent and 0.7 percent, respectively.