A U.S. proposal to build a 1,200-km fence along parts of its border with Mexico has drawn strong criticism from Mexican President Vicente Fox.
On Sunday, Fox described the latest immigration bill proposal passed by the U.S. Congress, as "a bad sign" for a country priding itself in its democracy.
"The vast majority of the US population, when we look at their roots, are immigrants who have arrived from all over the world and constructed that great nation," Fox said in Guanajuato, his home state.
The U.S. border fence plan, which includes spotlights and cameras along the 3,200 km border, has been described by Mexican officials as another Berlin Wall.
"Walls belong to the last century," Fox pointed out, adding that Mexico is the largest single consumer of U.S. products and services, more than that of Italy, France, Spain and Germany combined.
Almost 1.2 million people were arrested for illegally crossing the border from the Mexican side this year, most of whom are Mexican and Central Americans looking for a better life in the United States.
Meanwhile, some 11 million undocumented migrants live and work in the United States.
Remittances from Mexican workers in the U.S. to their home country, worth around 200 billion U.S. dollars each year, are one of the Central American country's largest sources of foreign exchange.
Mexico wants the United States to vote through a proposed program to offer illegal immigrants the chance to register and do, for up to six years, mostly low-skilled jobs which U.S. citizens are unwilling to take. They would then have to return to their home countries for a year to apply for a new work permit.