The convicted Mexican drug baron, also known as "El Chapo," escaped from jail on July 11 and has been on the run since. A nationwide search has failed to find any trace of him.

On Friday, a spokesman for the Mexican government confirmed it had received an extradition request from the United States for Guzman via a diplomatic note on June 25.

Interior Minister Miguel Angel Osorio Chong suggested to reporters late on Thursday that such a request had been made.

Guzman escaped the high security, Altiplano prison near the capital Mexico City through a mile-long tunnel that opened beneath his cell's shower. Two Mexican lawmakers said Thursday that at least 18 minutes passed before anyone in the jail was alerted.

Mexican prosecutors have formally taken 22 prison officials into custody on suspicion of helping Guzman escape.

The drug lord is head of the Sinaloa Cartel, a criminal organization named after the Mexican Pacific coastal state where it was formed.

In January, Mexican authorities had indicated Guzman would not be handed over to the US as he would serve his sentence in Mexico. Guzman is also wanted in the US on a series of charges including cocaine smuggling and money laundering.

Guzman had been arrested in February 2014, more than a decade after his last escape from a Mexican prison in 2001.

A nationwide search for Guzman is underway with checkpoints on major highways. Police have distributed 100,000 photos of Guzman to toll booths and put 10,000 agents on high alert since the escape.

jm/kms (Reuters, AP)