New Jersey Gov. Chris Christie will deliver keynote address when Republicans gather this month for their national convention before the November presidential election, the party said on Tuesday.

Christie, a colorful speaker popular among fiscal conservatives in his party, had considered a U.S. presidential run himself before endorsing Mitt Romney, who will become the official Republican presidential nominee at the gathering.

Reince Priebus, Chairman of the RNC, joins The Daily Rundown's Chuck Todd to talk about Mitt Romney's messaging plan for the GOP Convention and the medicare debate taking place on the 2012 field.

U.S. Senator Marco Rubio will introduce Romney at the convention, a Republican official also said. Rubio's home state of Florida - a battleground contest in November - will host the convention August 27 to August 30 in Tampa.

"As governor of New Jersey, Chris Christie has proven how bold Republican leadership gets results," Republican National Committee Chairman Reince Priebus said in a statement.

"We have an opportunity in Tampa to make clear that if we tell each other the hard truths, tackle the big problems, and make bold choices, we will see America's comeback," he said.

Christie, who is expected to seek re-election in 2013, has been a rising national figure in the Republican Party and has received praise for tax cuts, trimming the budget and other measures in his mid-Atlantic state.

The governor will argue for shared sacrifice to address the country's problems, according to USA Today.

As NBC's Chuck Todd reports, the battle is on to define Rep. Paul Ryan with Democrats trying to paint him as an ideological warrior determined to end Medicare and Republicans trying to sell him as the serious candidate with an intelligent plan to get the country out of debt.

"I'll try to tell some very direct and hard truths to people in the country about the trouble that we're in and the fact that fixing those problems is not going to be easy for any of them," he told the newspaper on Monday.

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Obama senior campaign adviser David Axelrod said Christie, with his lacerating wit, will be an entertaining speaker.

"I think that he'll do a great job for Governor Romney," Axelrod said Tuesday on CNN. "The problem for Governor Romney isn't his keynote speaker, it's his point of view."

Both Christie and Rubio had been mentioned as possible vice presidential picks. Romney on Saturday chose U.S. Representative Paul Ryan of Wisconsin.

Rubio is a Cuban-American who could help the party appeal to Hispanic voters.

Democrats, who hold their national convention September 3-7 in Charlotte, North Carolina, also chose a Hispanic politician, San Antonio Mayor Julian Castro, to deliver the keynote.