In a diplomatic letter, Garza said, "We do not expect Mexico to endorse every security measure we take, but we do trust that our neighbors will respect our right to take those measures on our own territory".

Mexico has harshly criticized legislation approved by the U.S. House of Representatives in December that would wall off large sections of the shared border, as well as making illegal immigration a federal offense and increasing sanctions for hiring undocumented workers. The initiative must still pass the Senate.

Garza also said he finds comparisons between the proposed border wall and the Berlin Wall "personally offensive." He said that in Germany, the wall was built to keep people trapped inside, but the initiative currently headed toward the U.S. Senate is simply a means of "protecting its own citizenry and enforcing our immigration laws."

Also on Friday, the Mexican Undersecretary of the Interior, Lauro López Sánchez said that the construction of walls along the U.S.-Mexico border has only succeeded in increasing the number immigrants who die attempting to cross into the United States.

López said that, although the numbers are still being calculated, at least 500 migrants died in 2005 while attempting to cross into the United States illegally, a dramatic increase from 2004.

Human rights organizations have argued that the walls built in strategic areas of the border since the 1990s, known as Operation Gatekeeper by the U.S. Border Patrol, has forced migrants to cross through more hostile terrain.

The Foreign Relations Secretariat reported 441 migrant deaths in the first 11 months of 2005. In 2004, it recorded 369 deaths of undocumented migrants.