WASHINGTON — The United States on Thursday moved to block seven international organized crime leaders from the country's financial markets, including a Japanese yakuza godfather and key members of a gang operating in four continents.

Under a new Obama administration order to disrupt global criminal organizations, the U.S. Treasury imposed sanctions on two leaders in a yakuza network involved in human trafficking, drug trafficking, extortion, prostitution and money laundering.

The godfather and deputy godfather of the most prominent yakuza crime family, the Yamaguchi-gumi, played key roles in directing the syndicate's policies and settling disputes with other groups, Treasury said. It estimated that the family generates billions of dollars a year in illicit proceeds.

Imposing sanctions on the Yamaguchi-gumi leaders, Kenichi Shinoda and Kiyoshi Takayama, as well as five members of the Brothers' Circle, a criminal group which operates in Europe, the Middle East, Africa and Latin America, forces U.S. financial institutions to freeze their assets in the United States.

"They use our financial system, they use our commercial system to both penetrate the markets, to disrupt the markets and to make use of their illicit proceeds," David Cohen, Treasury's undersecretary for terrorism and financial intelligence, told reporters.

Members of the Brothers' Circle who were subjected to sanctions ranged from a person in charge of production of drugs in Central Asia to two involved in drug trafficking and a shooting between regional factions within a Russian criminal network.

Treasury declined to provide details on the value of the assets the two crime networks hold in the United States. The department does not plan to publicly release the amount that will eventually be frozen.

As the organizations grow in size, strength, wealth and sophistication, Cohen said, one of the concerns is the threat that they pose to the financial industry and markets.

"One of the things that these organizations do is use the wealth they earn from illegal activities to try and infiltrate legitimate markets ... That creates distortion in the market that we are trying to address," he said.