Russia, which is separated from Iran in the south by three tiny South Caucasus nations and shares a sea border with the Islamic Republic, has been actively promoting a diplomatic solution to the Iranian issue.
"Any military action near our border is totally unacceptable," Andrei Denisov said. "We are strongly against it and we are doing our best to prevent it from happening."
Media reports in late March said Washington was preparing to strike at Iran in early April but Denisov denied the information.
"Our partners say movement of military structures in the Persian Gulf is part of a planned rotation," the diplomat said.
Yury Baluyevsky, the head of the Russian General Staff, warned Washington earlier Tuesday that it should think twice before launching a military campaign against Tehran as it would have global implications.
"Our strategic partners have already got bogged down in Afghanistan and Iraq," he said.
The U.S. Administration sees Iran as a "rogue state" and is determined to stop the Islamic Republic, diplomatically or otherwise, from obtaining nuclear weapons. Washington now plans to deploy a missile defense shield in Central Europe allegedly to protect itself from potential missile strikes from Iran or North Korea.
The UN Security Council passed a new resolution on Iran March 24 toughening economic sanctions against the country suspected of a covert nuclear program. Russia, which is building a $1-billion nuclear power plant in Iran, has resisted any strict sanctions against the Islamic Republic.