HOUSTON - US President Barack Obama on Tuesday renewed his call for comprehensive immigration reform, saying the country's immigration system needs genuine, comprehensive reform.

Obama made the remarks in El Paso, Texas, in his first visit to the southern US border as president, to highlight his efforts to secure the frontier with Mexico and to call for a route to citizenship for millions of illegal immigrants.

"We define ourselves as a nation of immigrants -- a nation that welcomes those willing to embrace America's precepts," he said.

"It doesn't matter where you come from. What matter is that you believe in the ideals on which we were founded, that you believe all of us are equal ... In embracing America, you can became American. That is what makes this country great," he said.

Comprehensive immigration reform has sparked furious debate in the United States in recent years. Both Democrats and Republicans are seeking to use the issue to their own advantage in the 2012 elections.

Republicans have indicated an unwillingness to consider broader changes, including a route to citizenship for undocumented immigrants, until the US-Mexican border is secured.

In El Paso, Obama called on the Congress to reject "the usual Washington games" and enact a comprehensive overhaul of the immigration system.

Obama said he had satisfied demands from the conservatives to step up security along the US-Mexico border and to increase deportation of illegal immigrants.

He called on the Congress to reform the immigration system in a manner that would allow skilled immigrants to participate in American society while ending what he called an underground economy that relies on illegal immigrant workers.

Obama had vowed to reform the country's immigration system during his presidential campaign in 2008, which helped him win critical support from an important and still growing constituency - - Hispanic voters.