The presidents of Belarus, Kazakhstan, and Russia are meeting in Astana for a summit of the Supreme Eurasian Economic Council.
The council is the governing body of the Customs Union of Russia, Belarus, and Kazakhstan.
Before the summit, Russian President Vladimir Putin and Kazakh President Nursultan Nazarbaev held separate talks on bilateral relations.
Putin said Moscow-Astana ties are effective and called Nazarbaev "the leader of the integration process."
The summit between Nazarbaev, Putin, and Belarusian President Alyaksandr Lukashenka will focus on further integration and plans to form a Eurasian Economic Union by 2015.
After the meeting, the three leaders are expected to hold talks with the presidents of Kyrgyzstan and Ukraine, Almazbek Atambaev and Viktor Yanukovych, respectively.
Kyrgyzstan wants to join the Customs Union, while Ukraine hopes to get observer status.
Based on reporting by Interfax, AP, and AFP