Washington.– Mexican Foreign Minister Luis Ernesto Derbez returned to his country on Tuesday without concrete results but having impressed on U.S. authorities Mexico's interest in such immigration reform as eschews a physical wall along the border and acknowledges the contribution Mexican workers make to the U.S. economy.

A Mexican diplomatic source said the objective of Derbez's trip was to "make known the Mexican government's point of view regarding the immigration issue and to address other regional issues."

"We do not seek to promote illegal immigration, as some believe in the United States. What we want is to continue talks" that lead to comprehensive immigration reform, the source added.

On Monday, Derbez met with U.S. Deputy Secretary of State Robert Zoellick and Undersecretary of State for Western Hemisphere Affairs Tom Shannon.

On Friday, he met with Cardinal Theodore McCarrick, archbishop of Washington, D.C., who heads the immigrant affairs committee of the U.S. Catholic Bishops Conference.

Derbez's visit, which is private in nature, is part of the Mexican government's ongoing campaign on behalf of U.S. policies that make for "legal, safe, orderly and humane" immigration.

Derbez's visit to Washington takes place just as the U.S. Senate prepares to take up the immigration issue once more, as positions harden pro and con.

On Dec. 16, the House of Representatives passed a bill sponsored by Republican Rep. James Sensenbrenner of Wisconsin, and supported by his party's most conservative wing, this is the toughest on illegal immigration in more than a decade.

Sensenbrenner's bill does not include President George W. Bush's guest worker program, one that would allow millions of undocumented immigrants to achieve legal status for up to six years.

In order to become law, the bill go through the Senate, where it faces an uncertain future.

Even though most senators support greater border security and tougher police action against illegal immigration, they also recognize the futility of massively deporting up to 11 million illegals.

Among other features, Sensenbrenner's bill envisages the construction of barriers along several stretches of the Mexican border, the employment of more Border Patrol personnel, expedited deportation of the undocumented and tougher sanctions on businesses that employ them.

Before embarking on his mission to Washington, Derbez had already described Sensenbrenner's bill as xenophobic, echoing the Mexican position that building fences at the border is not something friends or good neighbors do.

Mexican President Vicente Fox himself has said the House of Representative's endorsement of Sensenbrenner's bill is not only a step backward for bilateral relations but also reflects tolerance toward xenophobic groups in a country that prides itself on being a nation of immigrants.

Fox termed the idea of a wall between the two countries "shameful." If the immigration issue has not only raised hackles in the United States and Mexico but also deepened the immigration rift inside the country and even within the Republican Party, which controls both houses of Congress.

Groups that favor immigration reform point to immigrants' contributions to the economy and to the nation's social and cultural wealth.

According to a 2000 study by the Federal Reserve Bank of Dallas, immigrants contribute some $14 billion a year to the national economy, that is, 1.8 percent of the gross domestic product.

Undocumented immigrants make up 4.3 percent of the U.S. work force, but they play a major role in the nation's agricultural, construction and hospitality industries.

Groups that oppose legalization of undocumented immigrants insist they represent a public burden, displace U.S. workers and should not be rewarded for entering the country illegally.