Russia has already delivered nuclear fuel under a $1 billion contract to build the Bushehr plant, on the Gulf coast in southwest Iran. Iranian officials have previously said the reactor is likely to be started up in 2008.
Heat insulators for Bushehr were stopped on March 29 at the Azeri-Iranian border, Russian officials said. The Azeri Foreign Ministry said on Thursday the cargo could leave. Russia and Iran had each urged the other to do more to end the hold up.
"The consignment is on the way to Bushehr power plan after Azerbaijan received related documents (it) demanded from Russia," Foreign Ministry spokesman Mohammad Ali Hosseini was quoted as saying by the official IRNA news agency.
He added that the equipment was inside Iran.
Russia signed a contract to build the plant in 1995 based on an earlier project begun in the 1970s by the German firm Siemens. The project was disrupted by Iran's 1979 Islamic revolution and the 1980-88 Iran-Iraq war.
The United States and Russia say the plant means Tehran does not need to enrich uranium itself. Iranian officials say it is their right to have a domestic enrichment program, which worries the West because it can have civilian and military uses.
Russia has tried to push Tehran to be more open about its nuclear program and has warned the West against pushing Iran's leaders into a corner.
(Reporting by Hashem Kalantari, writing by Edmund Blair, Editing by Matthew Jones)
