to reform immigration laws on Tuesday, a campaign promise he made last year to Hispanics when running for re-election.
His speech in Las Vegas came a day after a bipartisan group of US senators unveiled the outlines of an immigration reform proposal that they will try to pass this year.
Many details still have to be worked out before the outlines can be translated into legislation. Here are the main elements:
* A PATH TO CITIZENSHIP: There are an estimated 11 million people living in the United States who arrived illegally. Most are from Mexico, Central American and South American countries.
The senators' plan would require those here illegally to register with the government and pass a background check. They would have to pay a fine and back taxes to earn a "probationary legal status."
Those people earning the status would go to the back of the line of prospective immigrants who have applied through legal means to come to the United States. They also will have to learn English and pay taxes to apply for a "green card" to live and work permanently in the United States.
From there, they could apply for citizenship.
* BORDER SECURITY MEASURES: The Senate plan is contingent on doing more to secure US borders, mainly the border with Mexico. This would include increasing the number of unmanned aerial vehicles and other surveillance equipment and adding border law enforcement agents.
An entry-exit system would be completed to track whether everyone entering the United States on temporary visas via airports and seaports have left the country as required by law.
Obama's plan does not make the green card process for illegal immigrants contingent on more border security measures, although he said he wants to see new penalties for cross-border crimes and a crackdown on businesses hiring illegal workers.
* HIGH-TECH WORKERS: The proposals include measures to keep and attract workers with backgrounds in science, technology, engineering and mathematics. This would be aimed both at foreign students attending American universities where they are earning advanced degrees, and high-tech workers abroad. US corporations have been lobbying for years for such a provision.
* YOUNG ILLEGAL IMMIGRANTS: Last summer, Obama gave a temporary reprieve from deportation to qualifying children who came to the United States with their parents. Under the Senate proposal, this group would not be subjected to the same requirements for being put on a path to citizenship.
* FARM WORKERS: The Senate plan sets up a special