Uzbek authorities said GUUAM has deviated from its initial goal of economic cooperation, focusing too much recently on security and political issues.
In Baku yesterday, Novguz Mamedov, head of the presidential administration's foreign relations department, said Uzbekistan's decision to leave GUUAM will not affect the further development of the organization.
In Kyiv, Ukrainian Foreign Ministry spokesman Dmirto Svistkov told RFE/RL's Ukrainian Service that Uzbekistan's withdrawal was not a surprise.
Svistkov said Uzbekistan in 2002 had already temporarily suspended its participation in GUUAM, and added: "The expansion of cooperation in the framework of GUUAM is determined by today's political situation, and demonstrates the increased role of this association in the region."
Ukraine's First Deputy Prime Minister Anatoly Kinakh said Uzbekistan may return to the group in the future.