U.S. President Barack Obama is set to meet with top Democratic Senate leaders on Wednesday to discuss stalled negotiations on how to raise the nation's borrowing limit and avoid a potentially catastrophic debt default.

President Obama will meet with Senate Majority Leader Harry Reid and other Democratic Senators following a news conference where the president is expected to address the debt ceiling dispute, among other topics.

On Monday President Obama held one-on-one talks with both Senator Reid and Republican Senate Minority Leader Mitch McConnell, though no progress was made on restarting joint negotiating sessions.

Talks stalled last week after Republican lawmakers walked out of debt ceiling negotiations chaired by Vice President Joe Biden, saying the White House was using the crisis to push for tax increases.

The United States risks defaulting on its $14 trillion national debt unless Congress acts to raise the legal limit on the amount the U.S. government is allowed to borrow by August 2.

Republicans, who control the House of Representatives, say they will not raise the debt ceiling without deep spending cuts. Democrats say Republicans are holding the debt ceiling vote hostage to an ultra-conservative fiscal agenda the Republicans could never enact on their own.

The head of the U.S. central bank, Benjamin Bernanke, says politicians must not allow the government to default on its loans, saying even a short-term break in payments could cause “severe disruptions” in financial markets. The Federal Reserve chairman also said the debt ceiling should not be used as a bargaining chip to force the government to reduce its spending deficit.

U.S. Treasury Secretary Timothy Geithner has also warned that the U.S. could face “catastrophic consequences” if lawmakers fail to raise the debt limit.