Mexican troops have made an historic seizure of 15 tons of pure methamphetamine in the western state of Jalisco, the Mexican army said in a statement released late on Wednesday.
Soldiers discovered the huge cache in the town of Tlajomulco de Zuniga, a suburb of Mexico's second-largest city, Guadalajara.
The statement had no other details but said it would publicly present the seizure on Thursday. Spokesmen answering the phone at the army's base in Guadalajara refused to comment further.
No one could say late on Wednesday what the largest seizure was previously in Mexico.
The United Nations Office on Drugs and Crime said total meth seizures worldwide were 34 tons in 2009, the most recent figures available.
The find outside Guadalajra is more than four times the size of a major seizure last summer of 3.4 tons and more than twice the total amount of meth seized in Mexico in 2009, according to the UN report.
Mexico is the primary source of the meth sold in the United States, according to US drug intelligence reports.
Methamphetamine production has been rising in Mexico, and much of the increase is attributed to the powerful Sinaloa Cartel, headed by Joaquin "El Chapo" Guzman, who the US Treasury Department calls the most powerful drug trafficker in the world.
Jalisco state has long been considered the hub of Sinaloa's methamphetamine trafficking, thought the army statement didn't indicate which Mexican cartel may have been involved.
The Sinaloa cartel also is suspected of smuggling in mammoth amounts of precursor chemicals that are used to produce meth in industrial-size operations.
It also appears to be extending its massive production of methamphetamine into neighboring Guatemala, where remote, isolated mountains and an alliance with a key Guatemalan trafficker are making the Central American nation a new international meth production base.
Mexican authorities seized 675 tons of a key precursor chemical in December alone, and all of it was heading for Guatemala.