Parliament deputies were to have voted on whether to proceed with controversial NATO-Ukrainian military exercises in the Crimea.
The adjournment was proposed by the Yuliya Tymoshenko Bloc, Our Ukraine, and the Socialist Party.
The three groupings, who acted as allies in the Orange Revolution in 2004, are expected to form a coalition government.
They have not, however, been able as yet to agree on cabinet appointments and other details.
Parliamentary elections were held in March.
In related news, Russia's lower house of parliament today warned Ukraine that its possible NATO membership would lead to "negative consequences for the entire range" of its relationship with Russia.
The warning came in a resolution approved by Duma lawmakers by a vote of 435-0. One deputy abstained.
Russian Foreign Minister Sergei Lavrov had told members of the Duma that the accession of Ukraine and Georgia to NATO that would amount to a "colossal geopolitical shift".
Ukraine's President Viktor Yushchenko has declared joining NATO a top priority for his country.
(compiled from agency reports)