Jan. 31 (Bloomberg) -- California Governor Arnold Schwarzenegger endorsed John McCain's bid for the Republican presidential nomination five days before the state's delegate- rich primary, calling him an ``American hero'' who is unafraid to work on bipartisan solutions.

``I am endorsing Senator McCain to be the next president of the United States because I am interested in a great future'' for the country, Schwarzenegger said after the two men toured a solar roofing manufacturer in Los Angeles. McCain has shown ``over and over again'' that he will reach ``across the aisle in order to get things done,'' the governor said.

The endorsement is a reversal of a vow the governor made earlier this month to stay neutral in the race.

Schwarzenegger's job approval rating among the state's Republicans was 68 percent in a December poll, and his backing may help deliver the state to McCain on Feb. 5. California, with 170 Republican delegates in the primary, is the biggest prize among the 21 states voting in the party's contests that day.

The second biggest state is New York, and McCain yesterday won the backing of Rudy Giuliani, the former mayor of New York City, who withdrew from the Republican race after finishing third in the Florida primary earlier this week. Giuliani appeared with Schwarzenegger and McCain at the Solar Integrated Technologies plant.

`Success Story'

McCain thanked Schwarzenegger ``for being the great American success story.''

``He came to this country with not very much except his strengths, his talents and his ambition,'' McCain, 71, said. ``I know that he serves as a role model and a guide to millions of Americans around the world.''

Schwarzenegger noted McCain's support for reducing greenhouse gases. McCain's advisers said the Arizona senator's position on climate change will allow him to attract independent, and younger, voters.

McCain ``knows that climate change is an issue with younger voters,'' said Senator Lindsey Graham, who traveled with McCain from Florida to California. ``It's one issue that he'll repair our damage with people overseas.''

McCain's chief rival, Mitt Romney, shrugged off Schwarzenegger's statement. ``We've got endorsements, he's got endorsements,'' he said as he campaigned today in Long Beach, California.

McCain today also was endorsed by former Senator John Danforth of Missouri, another state that will vote Feb. 5.

``In these uncertain times, John McCain is uniquely equipped to meet our challenges and lead our nation in the struggle against radical Islamic extremism,'' Danforth, also a former U.S. ambassador to the United Nations, said in a statement distributed by McCain's campaign.

To contact the reporter on this story: Hans Nichols in Los Angeles, California at 1871 or hnichols2@bloomberg.net

Last Updated: January 31, 2008 15:36 EST