Russia hit back Saturday at the United States after Washington had imposed sanctions on three Russian firms for exporting weapons to Libya and Iran, branding the US action "illegal". "The United States are not for the first time trying to extend their national laws illegally to foreign countries, forcing them to work according to Aemrican rules," the Russian foreign ministry said in a statement.

Washington announced sanctions Friday against 24 foreign entities, including Russian, Chinese and North Korean firms, for allegedly selling banned weapons to Iran and Syria.

Russian Defence Minister Sergey Ivanov said Saturday that as head of the commission controlling military exports he confirmed that "the three (Russian) companies did not violate any international norms on the non-proliferation of weapons of mass destruction and missile technologies," according to the Interfax news agency.

"It seems the American government is unhappy about the growing volume of arms and military equipment sold by Russia," the agency cited Ivanov as saying.

Russia's state-run arms exporter Rosoboroneksport was among the highest profile firms hit by the measures, imposed under the US 2005 Iran and Syria Nonproliferation Act.

The United States had already imposed similar sanctions on Rosoboroneksport and Russian plane maker Sukhoi in August 2006 for providing Iran with material that Washington said could be used to make weapons of mass destruction.

"Ultimately, all these decisions constitute an internal problem for the American authorities," the Russian foreign ministry said on Saturday.

"The American state is forbidding itself and American companies from cooperating with our leading businesses. In business terms, that means wasted opportunities," the ministry said.

Russian businesses had already strongly contested the measures on Friday, saying they were respecting international law.

Russia is one of the world's leading arms exporters. In 2005, it sold weapons to 61 countries for a record total of more than six billion dollars.