The U.S. Senate voted 68-32 on Thursday to approve the biggest immigration reform since 1986, opening the way for legalization and possible citizenship for an estimated 11 million undocumented immigrants.

Although the reform faces resistance in the Republican-controlled House of Representatives, the wide margin of approval in the Senate enormously increases the pressure in favor of an accord.

Fourteen Republican senators voted for the bill, including Florida Cuban-American Marco Rubio, seen as a possible 2016 presidential hopeful.

All the Senate Democrats, who hold a majority in the upper house, supported the proposed bill.

The reform, negotiated by the bipartisan "Gang of Eight" senators conditions legalization of undocumented foreigners to border security, drastically increases the monitoring of the nation's borders and establishes measures to control future immigration flows.

The vote, solemnly presided over by Vice President Joe Biden in his capacity as Senate president, was somewhat disrupted by a group of activists who, from the gallery, shouted "Si se puede!" (often mistranslated from Spanish as "Yes, we can!"), President Barack Obama's campaign slogan.

The vote puts an end to three weeks of intense debate that reflected ideological divisions around how to halt illegal immigration.

Democratic Senate Majority Leader Harry Reid said that the reform will strengthen U.S. economic and national security, although the majority of the Republicans who voted against it replied that it will not halt illegal immigration.

"Today, with a strong bipartisan vote, the United States Senate delivered for the American people, bringing us a critical step closer to fixing our broken immigration system once and for all," President Barack Obama said in a statement issued by the White House.

"Today, the Senate did its job. It's now up to the House to do the same," he said from Africa, where he is traveling on official business.

"If you're among the clear majority of Americans who support reform - from CEOs to labor leaders, law enforcement to clergy - reach out to your Member of Congress. Tell them to do the right thing," Obama said. EFE