"The 1977 Additional Protocols supplement the Geneva Conventions of 1949 and provide very important legal protections for civilians and others in both international and internal armed conflicts," his spokesperson said in a statement.
Additional Protocol I balances both military and humanitarian needs by bringing two previously separate areas of law: the law regarding the conduct of hostilities and the law protecting civilians and those who are actively participating in hostilities.
It prohibits the use of weapons which can cause excessive injury or unnecessary suffering, and reminds parties that the methods and means of warfare are not unlimited.
Additional Protocol II is the first of its kind to deal with civil wars, and it prohibits attacks on civilians and materials necessary for their survival.
To date, 167 States are party to Additional Protocol I and 163 are party to Additional Protocol II.
In a related development, the International Convention for the Suppression of Acts of Nuclear Terrorism - which aims to prevent such acts, bring perpetrators to justice and promote cooperation among countries - will enter into force 30 days from today.
Bangladesh became the 22nd State to accede to the Convention, which requires that many ratifications or accessions to enter into force.
"The Convention is expected to play a crucial role in preventing terrorists from gaining access to weapons of mass destruction," said UN Legal Counsel Nicholas Michel, welcoming the latest development.
The treaty will also "strengthen the international anti-terrorism legal framework by being a valuable addition to already existing universal counter-terrorism norms and obligations," he added.
With the addition of this Convention, there will be 13 anti-terrorism instruments covering such aces as hijackings, kidnappings, bombings and financing of terrorism.
Originally proposed by Russia, the Convention was adopted on 13 April 2005, and outlaws specific and concrete acts of nuclear terrorism. It is intended to protect against attacks on a range of targets, including nuclear power plants and reactors. It is also applicable to threats and attempts to commit such crimes.
The Convention - to which there are currently 115 signatories - also promotes cooperation among countries through the sharing of information and the providing of assistance for investigations and extraditions.