Senior Iranian and Russian nuclear officials have agreed that Iran's Russian-built Bushehr nuclear power plant will officially open next September and begin producing electricity by November 2007.
The officials say Moscow has also agreed to ship fuel for Iran's first atomic power plant by March.
Negotiators signed the agreement Tuesday in Moscow at talks between the head of Iran's Atomic Energy Organization, Gholamreza Aghazadeh, and Russia's Federal Nuclear Agency chief, Sergei Kiriyenko.
Iranian officials had expressed frustration that both fuel deliveries and the construction are behind schedule.
The United States has long been concerned that despite international safeguards, operating the Bushehr plant may provide Iran with valuable information that could be applied to a nuclear weapons program.
Russia has agreed to take back the plant's spent fuel so it cannot be used for weapons. But Iran has resisted a Russian proposal to conduct all of Iran's uranium enrichment on Russian soil.
Iran claims its uranium enrichment program is for peaceful purposes - mostly for providing fuel for nuclear power. The United States alleges the program is aimed at creating weapons-grade nuclear material.
Some information for this report was provided by AFP and AP.