The United States has imposed sanctions against seven foreign companies that allegedly had business dealing with Iran concerning sensitive technology.

By the action announced on Friday in the Federal Register, which reports on official federal actions, no U.S. government agency was allowed from dealing with any of the seven companies - two from India, two from Russia, two from the Democratic People's Republic of Korea, and one from Cuba.

The sanctions were imposed as these firms had passed on equipment or technology to Iran that could contribute to the development of weapons of mass destruction or cruise or ballistic missile systems, the Federal Register said.

The companies were found to be in violation of the Iran Nonproliferation Act of 2000, a law that is aimed at preventing the spread of weapons of mass destruction to Iran.

The sanctions, to take effect immediately, would be in place at least until July 28, 2008.