"We are talking about a purely technical delay," Tadic told the Tanjug news agency.
Russia and Serbia signed an agreement on January 25 as part of the South Stream project to construct a pipeline for the transit of Russian natural gas through Serbia to the Balkans and on to other European countries.
Tanjug reported on Thursday that Serbia's caretaker government had failed to ratify a January gas deal with Russia. Pro-Western ministers blocked a bid by nationalists to launch the ratification process for a key energy deal with Russia, stating that parliament and the government did not have the legal authority to undertake strategic agreements.
Only six out of 22 ministers voted in favor for the deal, and others refused to discuss it until after early elections due on May 11.
In March, pro-Western President Boris Tadic dismissed parliament and urged new elections after nationalist Prime Minister Vojislav Kostunica refused to govern alongside Tadic's Democratic Party over disagreements on EU integration.
The South Stream pipeline is expected to pump 30 billion cubic meters of Central Asian natural gas to Europe per year. Serbia and Hungary joined the project, already involving Italy and Bulgaria, earlier this year. Greece announced plans to join South stream last summer.
