By Charles Riley @CNNMoney

NEW YORK (CNNMoney) -- Outspoken New Jersey Gov. Chris Christie had some rather harsh words for billionaire investor Warren Buffett on Tuesday.

During a discussion with CNN's Piers Morgan about tax rates, Christie made it known that he's just about had it with Buffett, the world-famous investor who lent his name to a proposed tax hike on the rich.

He should just write a check and shut up," Christie said. "I'm tired of hearing about it. If he wants to give the government more money, he's got the ability to write a check -- go ahead and write it."

Earlier in the interview, responding to a question on class warfare in the political system, Christie, who has developed a reputation for not mincing words, said he didn't want to discuss Buffett.

"I'm so tired of talking about Warren Buffett," Christie said. "What are you going to bring up next, his secretary?"

First proposed by President Obama last year, the so-called "Buffett Rule" is intended to ensure that people making more than $1 million a year pay a higher share of their income in taxes than middle-class households.

To drive home the point, Buffett's secretary attended the State of the Union address in January. She pays a higher effective tax rate than her billionaire boss.

"Middle-class families shouldn't pay higher taxes than millionaires and billionaires. That's pretty straightforward," Obama said in September.

But the administration, in putting forth Obama's budget last week, made clear that they are not pushing to implement the Buffett Rule now. Rather, it's a guiding principle for when -- if -- Congress takes up tax reform.

Christie, one of Mitt Romney's most popular and visible surrogates, is frequently mentioned as a possible 2012 running mate for the Republican party's eventual nominee.

-- Piers Morgan's interview with Chris Christie will air at 9 p.m. ET and 12 a.m. ET.