The acting head of the Drug Enforcement Administration, Chuck Rosenberg, also says a tip-line for information about Guzman is being established.
Guzman escaped from one of Mexico's most secure prisons last month via a sophisticated mile-long tunnel that opened up in his cell's shower.
Mexican authorities have announced a $3.8 million reward for the drug kingpin, who's believed to have a net worth of about $1 billion.
