WASHINGTON, D.C., JAN. 13, 2009 (Zenit.org).- A U.S. bishops' official is urging the presidents of Mexico and the United States to cooperate in improving their nations' immigration situation.

Bishop John Wester of Salt Lake City, Utah, chairman of the bishops' Committee on Migration, made an appeal on the occasion of a meeting Monday between President-elect Barack Obama and President Felipe Calderón.

The prelate particularly urged the end of abuses committed against migrants, both in Mexico and the United States.

He also called for consideration of the factors that compel immigrants to undertake dangerous border crossings into the United States.

"Sadly, many [would-be immigrants] have died tragically in the American or Mexican desert," the bishop said. According to the episcopal conference, since 1994, more than 4,000 migrants have died attempting to cross the U.S.-Mexico border.

"The issue of illegal immigration transcends borders and must be addressed on a regional, if not hemispheric, level," Bishop Wester said. "The United States and Mexico must cooperate to ensure that policies are adopted that permit migrants to migrate and work in a safe and controlled manner.

"Today, they are subject to abuse and exploitation by unscrupulous employers and human smugglers and other criminal elements, as well as to lengthy and unnecessary detention in substandard jails."

The Church in the United States just finished its celebration of National Migration Week, which ended Saturday.

"Migrants risk their well-being and lives to migrate in order to find work and support their families -- it is a decision made out of necessity, not choice," Bishop Wester contended. "As a global institution present in both sending and receiving nations, the Catholic Church understands the economic and social forces that drive migrants to leave their families and home and seek work in another land.

"The two nations must build bridges of cooperation, not walls of separation."