WASHINGTON, Aug 7 (Reuters) - The United States on Tuesday targeted three Belize-based associates of Mexico's most-wanted man, cocaine king Joaquin Guzman, by freezing their U.S. assets as well as those of five of his companies including a banana farm, grocery store and marina.

The U.S. Treasury accused John Zabaneh, his nephew Dion Zabaneh and Daniel Moreno of being key associates of Guzman, who is the head of Mexico's Sinaloa Cartel. Americans and U.S. companies are now prohibited from doing business with the three Belize men and the five companies controlled by Zabaneh and Moreno.

Guzman and the Sinaloa Cartel have been identified by the United States as significant foreign narcotics traffickers under the U.S. Kingpin Act.

The companies blacklisted on Tuesday are Mayan King, Mid-South Investments, Crown Paradise Enterprises, Belize Chemicals and D's Supermarket Company.

Guzman, nicknamed "El Chapo," escaped a Mexican prison in a laundry cart in 2001 to become the country's most high profile trafficker.