The United States government on Thursday added a wife and son of Joaquin "Chapo" Guzman Loera, leader of Mexico's Sinaloa drug cartel, to its sanctions list.

The Department of Treasury designated Maria Alejandrina Salazar Hernandez and Jesus Alfredo Guzman Salazar, key operatives of the cartel.

The move bars U.S. citizens from doing business with them and freezes their assets under U.S. jurisdiction.

The Treasury said Jesus Alfredo, along with his father, was indicted on multiple drug trafficking charges in the U.S. District Court for the Northern District of Illinois in August 2009, while Maria Alejandrina provided material support to the drug trafficking activities of her husband and the Sinaloa cartel.

Guzman Loera and the Sinaloa cartel were identified by U.S. presidents as significant foreign narcotics traffickers in 2001 and 2009 respectively.

"Today marks the sixth time in the past year that OFAC has targeted and exposed operatives of the Chapo Guzman organization," said Adam Szubin, director of the Treasury's Office of Foreign Assets Control (OFAC).

"This action builds on Treasury's aggressive efforts, alongside its law enforcement partners, to target individuals who facilitate Chapo Guzman's drug trafficking operations and to pursue the eventual dismantlement of his organization, which is culpable in untold violence," he said in a statement.

Internationally, the Treasury has targeted more than 1,100 entities and individuals linked to 97 drug kingpins since June 2000.

Washington is aiding Mexico and Central American nations in fighting drug trafficking under the so-called Merida Initiative.