Upon Russia's request, the fuel will be removed from the reactor core of Bushehr nuclear power plant in order to conduct a number of tests and carry out technical work, Ali Asghar Soltanieh was quoted as saying by ISNA news agency.

He said nuclear fuel will be placed in the core of the reactor again after the tests are conducted.

Iranian Foreign Minister Ali Akbar Salehi said at the end of last month that Bushehr nuclear power plant was to join the national power grid in early April.

Salehi rejected claims that the launch of Bushehr power plant and its connection to the national power grid would be postponed again. "Everything with Bushehr nuclear power plant is progressing well," he said, "We hope in the mid-February, one or two weeks earlier or later, the nuclear power plant could join the national power grid."

He rejected reports that computer system in Bushehr was infected by a virus called Stuxnet, saying the computer worm could not go beyond personal computers and enter the facility's main system.

Some analysts believe it was Stuxnet that caused the delays of the plant's joining the national grid.

Russia signed an agreement worth one billion U.S. dollars with Iran in 1995 to take over the project. Its completion, initially scheduled in 1999, was postponed several times by mounting technological and financial challenges and interruptions under pressures from the United States.