The White House Tuesday knocked down a report that President Barack Obama feared that Republican Mitt Romney wants CIA chief and Iraq war hero David Petraeus as his running mate.
"Be mindful of your sources," White House spokesman Jay Carney told a reporter who queried him on the claim carried by the conservative-leaning website the Drudge Report.
Drudge had earlier thrown the explosive rumor into the melting pot of speculation surrounding Romney's looming announcement of his vice presidential nominee, expected within days.
The site, an online news pioneer, carried a story Tuesday quoting an "insider" as saying that Obama had whispered to a supporter this week that he thought Romney wanted to select the popular retired general.
"The president wasn't joking," the site quoted the "insider" as saying.
But Carney responded: "I can say with absolute confidence that such an assertion has never been uttered by the president."
"And again, be mindful of your sources."
Petraeus, renowned as the mastermind of the Iraq war troop surge strategy, who also served Obama as his top general in Afghanistan, was sworn in as new Central Intelligence Agency chief last September.
Asked whether Petraeus would make a good vice president, Carney replied "General Petraeus was an excellent general and is currently serving very well at the Central Intelligence Agency."
The idea of Petraeus leaving the president he serves as a top spy master to run against Obama on a Republican ticket appears exceedingly far-fetched -- not least because the former general has said he has no political ambitions.
It also seems highly unlikely he would leave the CIA, a vital cog in the US anti-terror campaign, without a leader less than a year after taking over.
Petraeus has repeatedly said he has no ambitions to pursue elective office, but has been dogged by rumors, partly because, after years in uniform, he appears highly adept at maneuvering through Washington's power politics.
"I am not a politician, and I will never be, and I say that with absolute conviction," Petraeus said on NBC's "Meet the Press" in August 2010.
The latest rumor may have more to do with Republicans fantasizing about a dream political scenario than fact, as they seek ways to neutralize Obama's perceived advantage on national security ahead of November's election.
Romney is expected to name his vice presidential pick within days, in the run-up to the Republican National Convention later this month in Florida.
The most often voiced possibilities are Ohio Senator Rob Portman and former Minnesota Governor Tim Pawlenty.
Outside chances are thought to include rising star Florida Senator Marco Rubio and even brash New Jersey Governor Chris Christie.