The United States has imposed sanctions on a Russian defense contractor said to have traded missile and other advanced weaponry to Iran.

The State Department imposed sanctions on the Federal Research and Production Center. The sanctions, which took effect on July 22, came amid a U.S. determination that Federal Research proliferated missile technology.

"We will continue to work hard with the Russian government to prevent Russian entities from contributing to weapons of mass destruction, missile programs or conventional weapons programs of concern that could aid terrorists or threaten the United States or our friends and allies," a State Department statement said.

Officials said the sanctions on the Russian company would last for two years, Middle East Newsline reported. During that time, the United States or companies would be banned from exporting to or trading equipment or technology with Federal Research. The company was not known to have any business in the United States.

The research center is located in Biysk, in the province of Altai. The department did not cite which country received the missile technology from the Russian firm.

But the State Department move was meant to have targeted Federal Research's trade with Iran, officials said. They said Iran has purchased missiles and components from the Russian defense firm for Teheran's Shihab-3 and Shihab-4 intermediate-range missile programs.

Russian officials and the company denied that that the research center traded with Iran. They said the center sold weapons components to India.

"The company observes all international obligations related to nonproliferation of missile and other technologies," Federal Research director-general Nikolai Tochilov was quoted by the Interfax news agency as saying. "In my view, these accusations are not substantiated."

Federal Research became the seventh Russian firm under U.S. sanctions. They included the Baltic State Technical University of St. Petersburg, Glavkosmos of Moscow, the Moscow Aviation Institute and the D. Mendeleyev University of Chemical Technology of Russia.

Two of the firms were accused of transferring weapons of mass destruction components to Iran. In April, the State Department lifted sanctions from six other Russian companies and a chemical weapons expert, Anatoly Kuntsevich.

The State Department's latest sanctions came as officials said Iran has sought to import deuterium gas from Russia. Deuterium gas, employed in heavy water reactors, was said to enhance the blast in nuclear explosions when combined with tritium. Russia has been the prime contractor of Iran's $1 billion nuclear power reactor at Bushehr.