President Barack Obama traveled Tuesday to the border city of El Paso, Texas, for a major speech in which he appealed to congressional Republicans to back immigration reform.

In shirtsleeves under the broiling Texas sun, the president visited a port of entry before addressing a crowd gathered at a national monument within sight of the border.

Calling immigration reform an "economic imperative," Obama urged Republicans to put politics aside in favor of legislation that would benefit the country.

A path to legalization for the nation's estimated 12 million undocumented immigrants will reduce the U.S. budget deficit by boosting tax revenues, while eliminating the scope for exploitation that keeps wages down, the president said.

"We need Washington to know that there is a movement for reform gathering strength from coast to coast," Obama said, asking supporters of immigration overhaul to organize and put pressure on Congress.

Lawmakers have shown little appetite for tackling immigration, a deeply divisive issue in the United States.

Republicans, who now control the House of Representatives, are mainly opposed to anything that smacks of amnesty for undocumented immigrants, preferring instead to concentrate on tightening the borders.

And even some in the president's own party are not onboard, as was made plain in December, when five Democratic senators effectively voted against the DREAM Act, a bill to legalize undocumented youths who enlist in the Armed Forces or attend college.

Listing the steps taken to better secure the border with Mexico, such as doubling the size of the Border Patrol and the construction of an elaborate fence, Obama said Tuesday that some Republicans will "never be satisfied."

"Maybe they'll say we need a moat. Or alligators in the moat," the president said, spurring laughter among the audience.

"So, the question is whether those in Congress who previously walked away (from immigration reform) in the name of enforcement are now ready to come back to the table and finish the work we've started," Obama said, vowing, "we're going to keep up the fight for the DREAM Act. We're going to keep up the fight for reform."

The president needs to reconnect with Hispanics if he hopes to win a second term in 2012.

Obama got 67 percent of the Latino vote in 2008, but the largest U.S. minority has become disenchanted over the president's failure to pass immigration reform, coupled with a dramatic increase in deportations under his administration.

His speech in El Paso followed a series of meetings at the White House with the Congressional Hispanic Caucus, activists and celebrities to discuss the best way to achieve immigration reform.