It said the move was in line with US extradition requests from 2014.
On Friday Guzman was detained and sent back to the maximum-security prison he escaped from six months ago.
Guzman, who was one of the world's most wanted drug traffickers, escaped from there in July through a tunnel dug in the showers.
That was his second escape - he was first arrested in Guatemala in 1993 and escaped from Puente Grande jail in 2001, reportedly in a laundry basket after bribing officials.
He was on the run for 13 years before being held again in 2014.  Previous requests from the US have been turned down.
Late on Saturday, Rolling Stone magazine published an article by US actor Sean Penn based on a meeting he had with Guzman at his secret hideout before his capture.
The two men discuss various topics, including drug trafficking. Guzman is quoted as saying: "If there was no consumption, there would be no sales.''
The extradition of "El Chapo" to the US is by no means a foregone conclusion. The two countries have an extradition treaty but there are many steps that need to be taken and officials that need to approve the request.
Many people believe that he should face justice in Mexico first. But the case goes beyond sovereignty and national pride.
Those CCTV images of Guzman slipping down from his prison-cell shower into a mile-long tunnel last year still haunt authorities. He has escaped not just once but twice from high-security prisons and there is concern his influence and financial clout could allow him to do it again.
With the headaches that Guzman has given President Pena Nieto, whose reputation was severely bruised by the escape, perhaps extradition is the safer bet.
Who is 'El Chapo' Guzman?
No detail was given about the time frame for an extradition but experts say the process could take months.
The attorney general's office said that lawyers for Guzman would have three days to file objections and 20 more days to prove them, though that timeframe could be extended, AFP news agency reports.
In a statement welcoming Guzman's recapture, Attorney General Loretta Lynch said Guzman had caused "significant violence, suffering and corruption on multiple continents".
The US filed requests in 2014 for his extradition so he could face charges of smuggling vast amounts of drugs into the country.
Guzman, who was named Public Enemy Number One by the Chicago Crime Commission in 2013, has been indicted by at least seven US federal district courts.
Guzman was arrested on Friday in the north-western city of Los Mochis in his home state of Sinaloa - which he had come to dominate through his drugs cartel.
During the raid, he managed to flee through a drain but was later caught by marines in a shootout.
Five suspects were killed in the operation and one marine wounded.
The Mexican attorney general's office says it will begin the process of extraditing recaptured drug lord Joaquin "El Chapo" Guzman to the US.