Russia's security chief issued a veiled warning to Washington on Sunday not to use the Iranian nuclear issue to try to change Tehran's political course.
"We oppose this question being used as an instrument of pressure, being used to interfere in Iran's internal affairs," said Igor Ivanov, the head of Russia's Security Council, Interfax news agency reported.

At the same time Ivanov, who is Russia's chief negotiator with Iran over its nuclear programme, called on Tehran to clarify unanswered questions about its uranium enrichment activities.

"For 18 years Iran conducted enrichment that was not under the control of the International Atomic Energy Agency. We insist that these questions be resolved," Ivanov told the Council for International and Defence Policy, a club of Russian officials and foreign policy specialists.

"If this issue is closed, then Iran will have the right to develop peaceful atomic programmess."

Washington accuses Iran of working to develop nuclear weapons, while Tehran insists its only goal is electricity generation.

A nuclear-armed Iran "would present a threat to Russia's interests both directly and indirectly. We will do everything to make sure this doesn't happen," Ivanov said.

He also said that Russia's suspension last week of plans to launch a nuclear power plant it is building near the Iranian town of Bushehr was not linked to Iran's possible pursuit of nuclear weapons.

"This is an independent question, and all the work that is done and continues there is under the strict control of the IAEA," he said.

Washington has consistently pressed Moscow not to launch the plant, which it fears could cover weapons-related work.