Mnatsakanyan previously served as Minister of Foreign Affairs[1][2] and Armenia's Permanent Representative to the United Nations.

Mnatsakanyan started his diplomatic career in 1991 as a Third then Second Secretary in the European Department of the Ministry of Foreign Affairs of Armenia.

In 1999 he was engaged in the preparations and was member of the Armenian delegation, headed by the President of Armenia, at the ceremony of the entering into force of the Partnership and Co-operation Agreement in Luxembourg.

In 2002 he was an active member of Armenia's negotiating team during the final stages of the accession to the World Trade Organization.

In 2006 he was also elected Vice-Chairman of the Executive Committee of the United Nations Economic Commission for Europe and participated actively in the reform of the Organisation.

He also headed Armenia’s delegation during the preparatory processes for the two World Summits on Information Society, in Geneva in 2003 and in Tunis in 2005.

As Deputy Minister of Foreign Affairs between 2011 and 2014 he was in charge of Armenia’s relations with Europe both at bilateral and multilateral levels.

Subsequently, between 2014-2017 these negotiated texts remained the foundation for the Armenia-EU Comprehensive and Enhanced Partnership Agreement, signed in 2017.

[7] As Ambassador, Permanent Representative of Armenia to the United Nations between 2014-2018 he was actively engaged in a broad range of priority issues, covering all three pillars of the Organization, including peace and security, development and human rights.

[8] During his tenure both in Geneva and in New York he had been actively engaged and on many occasions directly led the UN prevention agenda against atrocity crimes, including the initiation and negotiations leading to unanimous adoption of UN Human Rights Commission and Council respective resolution on the prevention of genocide in 2005 and 2008.

During his career, especially while working within the United Nations, he developed notable experience, knowledge and understanding of various regional issues and processes in many parts of the world.

On 16 November 2020, during the political crisis caused by the 2020 Nagorno-Karabakh ceasefire agreement, he resigned from his post, due to disagreements with PM Nikol Pashinyan.