Pacheco is widely regarded as one of Mexico's foremost poets
Mexican poet Jose Emilio Pacheco has been awarded the Cervantes Prize, the highest literary honour in the Spanish-speaking world.
The 70-year-old said he was overwhelmed by the award, for which he won 125,000 euros ($188,430, £114,000).
He is best-known for his accounts of adolescents growing up in a corrupt and unjust Mexico of the 1940s and 1950s.
The Cervantes Prize, which honours a writer's lifetime body of work, was created in Spain in 1975.
"It's like being hit by a punch that doesn't hurt you immediately, it's absolutely unreal," Pacheco said of his award from the international book fair in Guadalajara, Mexico.
"I'm very grateful and very happy, but I always think of other writers who deserve it much more than I do," he added.
Pacheco, a Mexico City native, is widely regarded as one of his country's foremost poets and short narrative writers, and a leading representative of his generation.
Jose Antonio Pascual Rodriguez, a member of the Cervantes Prize jury, said of Pacheco: "We've defined him as representing the whole of our language.
"He's an exceptional poet of daily life, with a depth, a freedom of thought, an ability to create his own world, an ironic distance from reality when it's necessary and a linguistic use that is impeccable."
He praised Pacheco's 1981 novel Las Batallas en el Desierto (Battles in the Desert), the story of a boy's infatuation with the mother of one of his classmates, calling it "a magnificent story that deals with childhood, adolescence and youth".
Pacheco has also translated works by Samuel Beckett, Tennessee Williams and TS Eliot and taught literature at universities in the US, UK and Canada, besides his work in Mexico.
Last year's Cervantes Prize, which is likened to a Nobel Prize for literature in Spanish, went to Spanish novelist Juan Marse.
Previous winners include Jorge Luis Borges of Argentina, Peruvian-born Mario Vargas Llosa and Carlos Fuentes of Mexico.