The project of Armenia's joining the Customs Union and the Common Economic Territory was requested to be prepared till June.

      The project on Armenia's joining the Single Economic Space was requested to be prepared before June 1, 2014, the chairman of the board of the Eurasian Economic Commission, Viktor Khristenko stated. "It was ordered to prepare the draft treaty on Armenia's joining the Customs Union and the Common Economic Space, formulated until June 1, for consideration by the meeting of the Supreme Council," he stressed. Earlier, Khristenko also said that all major differences on the draft treaty of a single economic space had been settled.

      The EaEU would create a single economic market of 170 million people and a gross domestic product of 2.7 trillion dollars. Armenia,Kyrgyzstan, Tajikistan and Uzbekistan have also expressed interest in joining the organization. In December 2012, Armenian President Serzh Sargsyan stated that EU, CIS and Eurasian integration need not be mutually exclusive. Maja Kocijancic, a spokeswoman for the EU High Representative of the Union for Foreign Affairs and Security Policy Catherine Ashton, responded that "if Armenia were to join any customs union, this would not be compatible with concluding a bilateral Deep and Comprehensive Free Trade Agreement between the EU and Armenia. Because a customs union has a common external trade policy and an individual member country no longer has sovereign control over its external trade policies." Although Armenia completed its negotiations with the European Union (EU) about signing Association Agreement in July 2013, on 3 September 2013, President of Armenia Serzh Sargsyan announced in Moscow that Armenia will join the Customs Union of Belarus, Kazakhstan, and Russia. A Russian government communique stated that, "Armenia [has] decided to join the Customs Union and take the necessary practical steps to subsequently participate in the formation of the Eurasian Economic Union." This decision was widely described as a "U-turn" by the Western media. On 2 October 2013, Sargsyan stated at the Parliamentary Assembly of the Council of Europe session that Armenia was ready to sign a deal with the EU during the Eastern Partnership Summit in Vilnius in November 2013, without the Deep and Comprehensive Free Trade Area component of the agreement that contradicts Armenia's membership in the EurAsEC Customs Union. This proposal was rejected by the EU and no deal was signed between Armenia and the EU at the Summit. 

      Although Armenia’s trade with EU states far exceeds that with EurAsEC Customs Union members Russia, Belarus and Kazakstan combined, Armenia is dependent on Russia for security.[36]Armenia's alliance with Russia is seen by Armenia as a counterbalance to Azerbaijan’s sharp hike in military spending (Azerbaijan bought tanks, artillery cannons and rocket launchers worth billions of US dollars from Russia in 2011, 2012 and 2013). This is seen by Armenia as a threat given that the Nagorno-Karabakh War (an armed conflict that took place from 1991 to May 1994 de-facto between Armenia and Azerbaijan) remains unresolved. Russia also has a military base in Armenia. 

      According to a poll conducted by Gallup International Association in October 2013, 64% of Armenians are in favor of Armenia's membership to the union. Of the six factions in theArmenian National Assembly, five have stated their support or their lack of opposition to the Armenian government's decision to join the union. Levon Ter-Petrosyan, Armenia's First President and the leader of the opposition Armenian National Congress, stated during a rally on 1 March 2014 that the decision is irreversible.

      Among the most notable opponents of Armenia's membership to the union are the four former foreign affairs ministers: Raffi Hovannisian (1991-92), Vahan Papazyan (1993-96), Alexander Arzoumanian (1996-98) and Vartan Oskanian (1998-2008).  Hovannisian, who officially came second in the 2013 presidential election, stated that Armenia's accession to the union "limits its sovereignty." Hovannisian's Heritage party is the only political party in the National Assembly that has stated its opposition. Other significant politicians who have stated their opposition include Former Prime Minister Aram Sargsyan and Soviet dissident Paruyr Hayrikyan.