The union has five members including Russia, Kazakhstan, Belarus, Kyrgyzstan and Armenia.
Few if any of Russia's former Soviet neighbours can escape the impact of its crisis, deepened by oil prices plunging to almost six-year lows, and the pain may encourage some to think more independently
Russia, Kazakhstan and Belarus leadership established asEurasian Economic Union entered into force as of today.
Expert says Armenia's membership in Eurasian Economic Union will make it more dependent on Russia
Signed agreement opens up new possibilities for Kyrgyzstan and Armenia, starting from 1st January 2015.
As Russia seeks to avoid international isolation because of Western sanctions over the Ukraine conflict, tension is growing rather than falling among the former Soviet states.
Kazakhstan's Foreign Minister Yerlan Idrisov said the Eurasian Economic Union was not formed out of a Soviet nostalgia.
While some investors have been quick to pull-out of Russia, others are increasing their shares.
The treaty forging the Eurasian Economic Union will come into force on Jan. 1, once it has passed the formality of being approved by the three former Soviet republics' parliaments.
With a market of more than 170 million people, the customs and trading bloc is intended by Putin to challenge the economic might of the European Union, the United States and China.
The Eurasian Economic Union will comprise Russia, Belarus and Kazakhstan. Moscow wanted Ukraine to join as well before its Moscow-backed president was ousted
The activists argue that joining the bloc would result in the limitation of Kyrgyzstan's political and economic independence.
It is also said that Syria is perparing to apply to join the Eurasian Economic Community Customs Union.
The Kazakh president set a goal of US$900 billion GDP in the Eurasian Economic Community by 2030.
Putin hopes the bloc will coordinate "economic and currency policy" among its members along the lines of the European Union.
"In both countries Assistant Secretary Biswal will re-affirm the U.S. commitment to continued engagement and partnership with the countries of the region for stability and prosperity," the State Department said in a statement.