Mitch Daniels (Darron Cummings/AP)

If Mitt Romney wants Indiana Gov. Mitch Daniels to be his running mate, he better get used to hearing a busy signal.

Daniels delivered his most forceful rejection of the vice presidential post yet, saying he would "disconnect the phone" if he found out that Romney was considering him for the job.

"It's not an office I want to hold, expect to hold, have any plans to hold," Daniels said during a Fox News interview Monday. "We ought to give some time to public service, try to pay back a little rent to this country, but my goal has always been to do the best I could and then go back to private life."

When asked if Romney had contacted him about vetting him for the job, he said "of course not," adding: "If I thought that call was coming, I would disconnect the phone."

The Mitt Romney campaign didn't waste any time to latch onto Newark Mayor Cory Booker's criticism of the Obama campaign's "nauseating" attack on Romney's Bain Capital record.

A day after Booker's controversial interview on "Meet the Press," the Romney campaign released an ad—"Big Bain Backfire"—using the Democratic mayor's comments slamming Barack Obama.

"Have you had enough of President Obama's attacks on free enterprise?" a voiceover in the minute-long ad says. "His own key supporters have."

"I have to just say from a very personal level, I'm not about to sit here and indict private equity," Booker said on Sunday's "Meet the Press."

The ad also uses similar comments from former Democratic Rep. Harold Ford Jr. on Monday's "Morning Joe" to rebut the Obama campaign's attack on Romney.

"Private equity is not a bad thing," Ford said. "As a matter of fact, private equity is a good thing in many, many instances."

U.S. President Barack Obama, Afghan President Hamid Karzai and Pakistani President Asif Ali Zardari (Pete Souza/White …

President Barack Obama spoke briefly with Pakistani President Asif Ali Zardari on the sidelines of a NATO summit as the uneasy allies looked to drain the poison from their wounded relations. Obama said he would not "paper over" tensions hampering efforts to negotiate a reopening of supply routes through Pakistan to NATO-led forces in Afghanistan.

"We're actually making diligent progress on it," Obama said at a press conference wrapping up the two-day gathering in his hometown of Chicago. Pakistan shut the supply lines after a November 2011 incident in which a U.S. airstrike on Pakistani soil killed 24 Pakistani soldiers.

"I don't want to paper over real challenges there," he said. "There's no doubt that there have been tensions between ISAF [International Security Assistance Force] and Pakistan, the United States and Pakistan over the last several months. I think they are being worked through."

Relations with Pakistan have been rocky -- or worse -- since the May 2011 raid that killed Osama bin Laden in the Pakistani garrison city of Abbottabad. American officials have suggested that some Pakistani government officials must have known that he was hiding there.