WASHINGTON (Reuters) - President Barack Obama urged key Republican senators on Tuesday to help produce bipartisan legislation as soon as possible for a sweeping immigration overhaul that includes strengthened border security and an "earned path" to citizenship for illegal immigrants in the United States.

Obama spoke by phone to three U.S. senators, Marco Rubio, John McCain and Lindsey Graham, part of a group of Republican and Democratic lawmakers working on an immigration reform package.

"As the president made clear when he met with Democratic senators involved in the process last week, that while he is pleased with the progress and supportive of the effort to date, he is prepared to submit his own legislation if Congress fails to act," the White House said in a statement.

(Reporting By Matt Spetalnick and Robert Rampton)