The National Human Rights Commission, a Mexican government-funded agency with independent powers, has said it would distribute at least 70,000 maps showing highways, rescue beacons and water tanks in the Arizona desert.
''It is a bad idea to encourage migrants to undertake this highly dangerous and ultimately futile effort,'' Chertoff said. ''This effort will entice more people to cross, leading to more migrant deaths and the further enrichment of the criminal human trafficking rings that prey on the suffering of others.''
The Mexican human rights panel, however, denies the maps will encourage illegal immigration. The commission said this week the maps would help guide those in trouble to find rescue beacons and areas with cell phone reception. The maps will also show the distance a person can walk in the desert in a single day.
Rafael Laveaga, spokesman for the Mexican Embassy in Washington, said it is not the policy of the Mexican government to encourage undocumented immigration ''in any way.'' He also emphasized that the commission is an independent agency.
The administration of Mexico President Vicente Fox has tried to establish mechanisms for migration that are ''legal, safe and respectful of human rights,'' Laveaga said.
''Let's face it, we and the United States have not been able to establish those mechanisms,'' he said.
The commission will begin putting up the poster-size maps in March in places where migrants will see them.
Mexico was criticized last year for distributing a similar comic-style guide booklet. It warned of the perils of crossing illegally into the United States, while offering tips to stay safe.
Illegal immigration has become a big issue in the United States and is certain to become more volatile during the midterm elections.
President Bush has been pushing since he took office for a temporary worker plan as a way to control illegal immigration across the U.S.-Mexico border, but he has been opposed by some who consider the plan amnesty.
The House passed a ''border security'' bill late last month that includes proposals to build fences in five cities along the U.S.-Mexico border and to enlist the military and local law enforcement to stop illegal entrants. The House legislation did not include Bush's guest worker proposal.
The Senate has not yet passed an immigration bill. Once it does, senators will meet with members of the House to hash out differences in their legislation. Many immigration advocates don't expect the Senate to include many of the House measures.