Ukraine is disappointed with the Commonwealth of Independent States, a loose alliance of ex-Soviet republics, and may consider withdrawing if the group cannot prove its usefulness, a senior aide to President Viktor Yushchenko said Friday.

"If there aren't going to be results, this question will arise, if not tomorrow then in the nearest future," said Kostyantyn Tymoshenko, Yushchenko's foreign policy adviser.

The CIS was created after the 1991 Soviet collapse, but the Moscow-dominated group has been eyed with increasing suspicion by its more pro-western members, Ukraine and Georgia, which have sought in recent years to move out of the Kremlin's shadow.

Georgian President Mikhail Saakashvili is currently studying the possibility of quitting the group. Tymoshenko said such a move wasn't on Ukraine's agenda today, but noted that "we have said more than once that we are not pleased with how the CIS functions."

Last month, the 12-member organization rejected a request by Kiev to recognize the 1930s famine in Ukraine as genocide. Ukraine has also tussled with the group over alleged bias in its election observer missions. Under Yushchenko, who defeated a Kremlin-backed candidate for the presidency in 2004, Ukraine has begun a pro-western drive, aiming for future membership in NATO and the European Union.

"The CIS is turning into a club whose members talk instead of solving problems," Deputy Foreign Minister Volodymyr Ohryzko said later Friday, after returning from negotiations in Russia over the status of Russia's Black Sea Fleet in a Ukrainian port.