The U.S. Treasury Department has designated a New York-based company as a front for an Iranian bank that Washington says helps spread weapons of mass destruction.

The Treasury Wednesday said it is freezing the U.S. assets of ASSA Corporation, which runs a building on New York City's Fifth Avenue, and its parent company, ASSA Corporation Limited, located in the Channel Islands.  The order also prohibits Americans from doing any business with them.

The United States accuses the companies of fronting for Iran's Bank Melli, funneling money from the United States to Iran in what a Treasury official calls "yet another example of Iran's duplicity."  Treasury says Bank Melli is a "known proliferator" of weapons of mass destruction.

The Acting U.S. Attorney for the Southern District of New York Lev Dassin praised the investigative work of the FBI, New York City police, and the Internal Revenue Service.

The United States has supported three rounds of United Nations sanctions on Iran for its disputed nuclear program.  It also has taken unilateral action on various Iranian entities.

Some information for this report was provided by AP.