It was earlier reported that the NPP will be launched in September 2007, and will begin supplying the national grid in November 2007.
"The approved schedule for the Bushehr power plant's launch envisages a whole set of arrangements, including by the Iranian side, and it could be revised if the Iranian side fails to meet the schedule," the source said.
The plant has been a source of international dispute in the context of Iran's controversial nuclear ambitions, with the United States urging Russia not to build the plant, while Russia has consistently defended Iran's right to nuclear power.
European countries have proposed a draft UN Security Council resolution on sanctions against Iran, under which the Bushehr NPP would not be banned, but nuclear fuel supplies to the plant would be restricted, a proposal that Russia wants removed from the document.
The EU-3 - Britain, France and Germany - proposed two weeks ago an array of sanctions against the country for its refusal to suspend uranium enrichment, which includes banning sales of missile and nuclear technologies to Iran, freezing its military bank accounts, and imposing visa restrictions on officials linked to the nuclear industry.
The Russian nuclear official also said a proposal to set up a Russian-Iranian joint venture to enrich uranium may never materialize.
"We are not satisfied with Iran's response to our proposal," the Russian official said, adding that the proposal was not currently under discussion.
