Mexicans thinking of crossing illegally into the USA can now get a book of tips on how to make the journey safely.
The guide includes tips on legal rights while in US custody
A 32-page comic guide with advice on surviving the hazards of the trip is published by Mexico's foreign ministry.
Would-be migrants are told to add salt to water to avoid dehydration in the Arizona desert, and where to swim across the Rio Grande.
US pressure groups have accused the Mexican government of encouraging illegal migration with the "manual".
Each day thousands of Mexicans enter the US on foot via the Arizona desert in the hope of finding work.
Mexico says it has a duty to protect its citizens many of whom die each year crossing the long and dangerous border.
Not crossing a river alone and at night
Wearing light clothing - "heavy clothing becomes heavier when wet, and this makes swimming or floating difficult"
Adding salt to fresh water to avoid dehydration
Walking during times of low heat
It also informs immigrations of their medical and legal rights if they are taken into custody in the US and how to avoid trouble across the border.
"Last year over 300 Mexicans died in their attempt to enter the United States in search of a job and the government has the obligation to avoid that," said Geronimo Gutierrez, Under-secretary for North American Affairs at Mexico's foreign ministry.
"The guide clearly states that the safe and appropriate way to enter any country is with a valid passport and a visa, and in no way promotes undocumented immigration," Mr Gutierrez said.
US pressure groups say they are concerned.
"With this document the Mexican government not only has not instructed its citizens to obey immigration law but, in rich detail, it has supplied a manual on how to circumvent US immigration law," said John Keeley, director of communication for the Center for Immigration Studies in the US.
"It's very, very troubling."
The US State Department has issued a statement praising co-operation with the Mexican authorities in improving safety along the border.