Mexican drug lord Joaquin "El Chapo" Guzman is "the world's most powerful drug trafficker", the US Treasury Department said.

The fugitive Sinaloa cartel leader also got a boost from Mexican actress Kate Del Castillo, who said she believed in Guzman more than in the government.

It was the latest in an odd series of accolades for Guzman, who was included this year on the Forbes list of the world's richest people, with an estimated fortune of one billion US dollars.

The US Embassy in Mexico City issued a statement saying three of Guzman's alleged associates had been hit with sanctions under the drug Kingpin Act, which prohibits people in the US from conducting businesses with them and freezes their US assets.

The two Mexican men and a Colombian allegedly aided Guzman's trafficking operations.

The statement quoted Adam J Szubin, director of the Treasury Department's Office of Foreign Assets Control, as saying the move "marks the fourth time in the past year that OFAC has targeted and exposed the support structures of the organisation led by Chapo Guzman, the world's most powerful drug trafficker".

Guzman, who escaped from a Mexican prison in 2001 in a laundry truck and has a seven million US dollar bounty on his head, has long been recognised as Mexico's most powerful drug baron.

Authorities said his Sinaloa cartel has recently been expanding abroad, building international operations in Central and South America and the Pacific.

Del Castillo, who played a female drug trafficker in the TV series La Reina del Sur (Queen of the South), offered grudging praise for Guzman in a posting on the social media site Twextra, linked to her Twitter account.

"Today, I believe more in El Chapo Guzman than in the governments who hide truths from me," she wrote.

PA