After putting controversial cuts to Social Security and Medicare on the table in negotiations with congressional Republicans over a plan to raise the nation's debt ceiling, President Obama still doesn't have a deal in the works. Emerging from a meeting with congressional leaders on Thursday, Obama said that both sides in the negotiations would find the ultimate outcome "painful." He also explained that the two sides had not yet arrived at an accord, but would reconvene talks on Sunday.

"I want to emphasize that nothing is agreed to until everything is agreed to," Obama said, adding that the talks were conducted "in a spirit of compromise" but that the parties "are still far apart on a wide range of issues."

Both sides must come to a resolution to raise the $14.3 trillion limit by August 2, or the federal government could risk default, Treasury officials warn.

Obama has offered to reform the nation's entitlement programs in return for a deal that would increase government revenue by closing loopholes in the tax code.

House Republicans met behind closed doors on Capitol Hill earlier this morning to hash out their game plan for the meeting with Obama later today, and emerged to say that tax increases--of any kind--were "off the table."

"Everything's on the table except raising taxes on the American people," House Speaker John Boehner (R-OH) said shortly after the meeting. At this point, however, "there is no agreement," he added.

Cantor suggested Wednesday that Republicans could accept a deal to close tax loopholes if they are matched with tax reductions. Boehner said Thursday that comprehensive tax reform was a viable option in the talks with the White House.

"We believe that comprehensive tax reform, both on the corporate side and the personal side, will make America more competitive, help create jobs in our country, and is something that is under discussion," he said.

Meanwhile, coalitions within both parties are trying to keep their leaders from giving up too much in the talks. Democrats, especially the party's Progressive Caucus, are demanding that tax loopholes and certain credits for business be eliminated from the tax code, and want a tax increase on those earning more than $250,000. On Thursday, caucus leaders again voiced their opposition to any deal that touches Social Security or Medicare and sent a letter to the president urging him reject any Republican efforts to reform the programs.

"[A]ny cuts to Social Security, Medicare and Medicaid should be taken off the table," the letter read. "The individuals depending on these three programs deserve well-conceived improvements, not deep, ideologically driven cuts with harmful consequences."

The leaders of the caucus have requested a special meeting with Obama to air their concerns.

Liberal activists, too, have vowed to punish Democrats if they go along with a deal that cuts Social Security. The liberal group MoveOn.org unveiled a poll of its members this week that showed that 76 percent of them said they would be "less likely" to volunteer for the president in 2012 if cuts are made to Social Security.

For Republicans, the conservative wing of the party has put forth a plan to cut trillions from the federal budget on top of a promise of a constitutional amendment that forces the federal government to balance its budget every year. Republican leaders have not said whether a Balanced Budget Amendment is included in the talks with the president, but 28 GOP House members and 12 Senators have said they won't support a deal without the amendment.

Any final arrangement between congressional leaders and the president will require support from both parties to pass. But with liberals and conservatives pulling hard in both directions, any deal the leaders agree to could be a tough pill to swallow for both parties.