The delegation, led by Mahmoud Hanatian, Vice President of the Iran's Atomic Energy Organisation visited the Kalinin nuclear power station in Tver region, 300 kilometres from Moscow, as part of a three-day visit to Russia.

Mahmoud Hanatian said Iran is working closely with Russia to establish a nuclear power plant.

"I hope that our power plant will be finished as soon as possible by Russia. And after that some experts from Kalinin (will) come to Iran and will have some discussions with our employees in Iran."

Russia has stipulated that all of the plant's spent fuel must be returned to Russia; a measure designd to prevent Iran from reprocessing the spent fuel into plutonium.

The visit followed Iran's written response to the package of incentives offered by the United States and five other world powers, including Russia, for Iran to roll back its nuclear program.

Iran said it was ready for "serious negotiations."

Meanwhile in a speech during Friday prayers in Tehran, Ahmed Khatami, a member of Iran's Expediency Council, which arbitrates between parliament and the ruling hierarchy, advised the Security Council not to test Iran's resolve.

"Talking with the language of threat and force with Iran is stupid and unwise."

Khatami referred to the recent holding of war-games in Iran and said that the Iranian military would make any aggressors regret their actions if they attacked Iran.