The Bush administration imposed financial sanctions on an Iranian state-owned financial institution on Thursday for allegedly providing financial services in support of the country's weapons programme.

The Treasury Department's action means that any bank accounts or other financial assets belonging to the Export Development Bank of Iran that are found in the United States are frozen. Americans also are prohibited from doing business with the bank.

The government contends the bank provided financial services to Iran's Ministry of Defense and Armed Forces Logistics, which controls Iran's ballistic missile research, development and production activities. The US also alleges that Iran was using the bank to evade international sanctions.

"Iran has adopted a strategy of using less prominent institutions, such as the Export Development Bank of Iran, to handle its illicit transactions," said Stuart Levey, the Treasury Department's undersecretary for terrorism and financial intelligence.

He said today's action exposes the export development bank's role "in helping Iran violate UN sanctions so that financial institutions around the world can take appropriate steps to protect themselves."

Treasury also acted today against three entities that the United States believes are owned, controlled or act on behalf of the Export Development Bank of Iran. They are the EDBI Stock Brokerage Co and EDBI Exchange Co, both in Tehran, and Banco Internacional De Desarollo in Venezuela.

The US government alleged that the Export Development Bank of Iran provides financial services to multiple entities connected to Iran's Ministry of Defense and Armed Forces Logistics. That has enabled those entities to "advance Iran's WMD (weapons of mass destruction) programmes," Treasury said.