Russia expects all three member states of a new customs union to actively contribute to the work it carries out, Russian Prime Minister Vladimir Putin said on Thursday.
The Customs Union between Russia, Belarus and Kazakhstan formally came into existence on January 1, 2010, but is unable to start working fully until disputes are resolved and the customs code comes into effect.
Russia and Kazakhstan have already ratified the document.
Two sources said on Wednesday that the Belarusian parliament had ratified the customs code but there has as yet been no official confirmation.
A meeting of the Eurasian Economic Community (EurAsEC) Intergovernmental Council is due on July 5 in the Kazakh capital, Astana, where a range of issues surrounding the prospects for EurAsEC and the Customs Union will be discussed.
EurAsEC comprises Kazakhstan, Russia, Belarus, Kyrgyzstan and Tajikistan. Its intergovernmental council doubles as the top body of the Customs Union.
First Deputy Premier Igor Shuvalov said customs posts in the united customs territory would be abolished by July 1, 2011.
"The united customs territory will either be made up of the geographical territories of Russia and Kazakhstan, or it will be composed of the three states, including the Republic of Belarus," he said.
The Russian prime minister said Russia was not against the idea of other countries joining the Customs Union.
"In spite of fears, I am confident that we are doing the right thing. It is Russia's historic choice to follow the path of integration with our closest neighbors and partners," Putin said at government meeting.
"The door for such integration and for a deeper level of integration is open. Anyone who wants to use [this opportunity] will be able to," he said.