Russian news agencies are reporting the reactor at a nuclear power plant that Russia is building in Iran will not be switched on this year as planned.

The agencies quote Energy Minister Sergei Shmatko as saying Monday that while Russia expects to make "serious progress" by the end of the year, "there will be no startup."

Officials in Russia and Iran previously announced plans to switch on the reactor this year.

The plant near the city of Bushehr is part of a nuclear program that Iran says is peaceful. The U.S. and Israel claim Iran is working to develop nuclear weapons.

Russia also says Iran must not acquire nuclear weapons, but it has close ties with Tehran and has pledged to complete the more than decade-old project.