WASHINGTON -- President Barack Obama, at a surprise news conference Monday, called on presumptive GOP nominee Mitt Romney to release more years of his tax returns, linking the disclosure to the debate over tax reform.

"I think that is what the American people would rightly expect, is a sense that particularly when we're going to be having a huge debate about how we reform our tax code and how we pay for the government that we need, I think people want to know that everybody's been playing by the same rules, including people who are seeking the highest office in the land," Obama said.

"This is not an entitlement, being president of the United States," he continued. "This is a privilege and we've got to put ourselves before the American people to make our case."

Later in the briefing, Obama clarified that his use of the phrase "playing by the same rules" was not meant to accuse Romney of doing anything illegal. "There's a difference between playing by the same set of rules and doing something illegal. In no way have we suggested the latter," he said.

"I'm not asking to disclose every detail of his medical records, although we normally do that as well," he said to laughs. "This isn't overly personal here, guys. This pretty standard stuff. I do not think we are being mean to ask him to do what every other presidential candidate has done."

The Romney campaign did not return a request for comment on the president's remarks.

Mitt Romney has steadfastly refused to release more than his (likely incomplete) 2010 tax return and his 2011 return, which the campaign plans to release before Oct. 15, according to a Romney adviser.

"There's going to be no more tax releases given," Ann Romney said Wednesday.

Obama and Vice President Joe Biden have each released 12 years of tax returns. Since 1980, only Sen. John McCain (R-Ariz.) released just two years of tax returns, while all other major party candidates have released at least five.

Romney said Thursday that he had never paid less than 13 percent in taxes over the past ten years, rebuking Senate Majority Leader Harry Reid (R-Nev.), who said a Bain Capital investor told him Romney paid no taxes for ten years.

Also on HuffPost:

Loading Slideshow...
  • Ron Paul

    "Politically, I think that would help him," Paul said in a interview with <a href="http://www.politico.com/news/stories/0712/78599.html#ixzz20w7ycTBE" target="_hplink">Politico</a>. "In the scheme of things politically, you know, it looks like releasing tax returns is what the people want."

  • Richard Lugar

    "I have no idea on why he has restricted the number to this point," <a href="http://www.cbsnews.com/8301-18563_162-57474352/pressure-mounts-on-mitt-romney-to-release-more-tax-returns/?tag=socsh" target="_hplink">Lugar said</a>.

  • George Will

    "I don't know why... he didn't get all of this out and tidy up some of his offshore accounts and all the rest," Will said on ABC's "<a href="http://www.huffingtonpost.com/2012/07/15/george-will-mitt-romney-bain_n_1674513.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+HP%2FPolitics+(Politics+on+The+Huffington+Post)" target="_hplink">This Week</a>." "He's done nothing illegal, nothing unseemly, nothing improper, but lots that's impolitic."

  • Bill Kristol

    "He should release the tax returns tomorrow. It's crazy," Kristol said on "<a href="http://www.huffingtonpost.com/2012/07/15/mitt-romney-tax-returns_n_1674325.html" target="_hplink">Fox News Sunday</a>." "You gotta release six, eight, 10 years of back tax returns. Take the hit for a day or two."

  • Robert Bentley

    "I just believe in total transparency," Bentley told <a href="http://abcnews.go.com/blogs/politics/2012/07/gop-governor-calls-on-mitt-romney-to-release-additional-tax-returns-and-show-he-has-nothing-to-hide/" target="_hplink">ABC News</a>. "In fact, I was asked today that question -- do you think that Governor Romney should release his tax returns? And I said I do. I said, I release my tax returns. I may be the only public official in Alabama that does, but I release mine every year and I just believe that people should release their tax returns. And if you get them out and just get past that, it just makes it so much easier."

  • Haley Barbour

    When asked on "<a href="http://www.nationaljournal.com/2012-presidential-campaign/barbour-romney-should-release-more-tax-returns-20120710" target="_hplink">The Situation Room</a>" if Romney should release more returns, Barbour said, "I would. But should it be an issue in the campaign? I don't think it amounts to diddly."

  • Michael Steele

    "If there's nothing there, there's no 'there' there, don't create a there,'" Steele said on MSNBC.

  • David Frum

    "Tax returns the next problem. Releasing returns under pressure: more weakness, more pain," Frum <a href="https://twitter.com/davidfrum/status/224509505973661696" target="_hplink">tweeted</a>.