Armenian President Vahagn Khachaturyan approved the parliament's decision to join the International Criminal Court in a move that has further strained the country's ties with its old ally Russia.
Last week, Armenia's parliament voted to join the ICC by ratifying the Rome Statute that created the tribunal.
Countries that have signed and ratified the Rome Statute are bound to arrest Russian President Vladimir Putin, who was indicted for war crimes connected to the deportation of children from Ukraine, if he sets foot on their soil.
Moscow last month called Yerevan's decision an “unfriendly step,” and the Russian Foreign Ministry summoned Armenia's ambassador.
Armenia later sought to assure Russia that Putin would not be arrested if he entered the country.
Armenian officials have argued the move has nothing to do with Russia and was prompted by what they call Azerbaijan's aggression against the country.
Lawmakers voted to ratify the Rome Statute by a vote of 60-22. The decision comes into force 60 days after the ratification, according to Armenian lawmakers.
Armenia had started the process of joining the tribunal more than 20 years ago, but in 2004 the Constitutional Court ruled that the Rome Statute contradicted the country's constitution at the time, putting the process on pause.
The constitution has been amended twice since then. In March, the Constitutional Court ruled that the obligations for signatories outlined by the Rome Statute are in line with the existing constitution.
Armenia's envoy on international legal matters, Yegishe Kirakosyan, said Yerevan decided to resume the process of joining the ICC because of Azerbaijan's alleged moves against Armenia.
Last month, Azerbaijan routed the ethnic Armenian separatist forces in Nagorno-Karabakh and recaptured the enclave.
