(CNN) - One-time Mitt Romney rival Rudy Giuliani endorsed the all-but-certain Republican presidential nominee for president on Monday. And the former New York City mayor downplayed any chance he would be considered a running mate on the GOP ticket.
Giuliani made his endorsement in an appearance on Fox News, saying that Romney's "got the resume and background for the job."
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He added that when it comes to the economy and foreign policy, Romney is the right choice come November, over President Barack Obama.
"I think he has an understanding of the economy that's far deeper than the president and far deeper than most people, and I think he has the strength and toughness to handle foreign policy," Giuliani said.
The former mayor and 2008 GOP presidential candidate said he met with Romney last week.
"I had a very good breakfast with him. We had a very long talk," Giuliani said. "Of course we've talked a number of times. This was a really good long talk."
Giuliani and Romney were rivals in the last battle for the GOP presidential nomination, with both candidates losing to Sen. John McCain of Arizona. Earlier this cycle Giuliani said nice things about presidential candidate and former House Speaker Newt Gingrich, and had some critical comments of Romney. But when it came to the race for the nomination, he said "Mitt has won fair and square."
As for being considered a running mate to the former Massachusetts governor, Giuliani said "I'm not on the list for running mate. I'm sure of that."
But Giuliani then went on to say: "But I would help him in any way that I could, anything I can do."
Last year Giuliani flirted with a second run for the GOP nomination before deciding against making another bid for the White House.
Following the interview, Romney's presidential campaign released a statement.
"I'm very proud to earn the support of such a distinguished leader and public servant to our country," Romney said. "Rudy's successes in turning around New York City are well-known and his name is synonymous with leadership, uniting a city in the aftermath of the worst terrorist attack in our nation's history. I look forward to his help in the months ahead as I work to restore America's promise and reverse President Obama's failed policies."