WASHINGTON – President Obama likely will step into the final stages of talks to break a deadlock over a plan to cut budget deficits, his spokesman said Thursday after two Republicans dropped out of talks led by Vice President Joe Biden.

House Majority Leader Eric Cantor cited an “impasse” over tax increases in refusing along with Sen. Jon Kyl of Arizona to attend Thursday’s negotiating session. They called for Obama to take the lead.

The move caught Democrats by surprise and raised the prospect that the Biden-led talks could collapse over taxes. Republicans insist on major spending cuts, and no tax increases, before they will agree to raise the nation’s $14.3 trillion debt ceiling. The Treasury Department says the limit must be raised by Aug. 2 or the United States will risk defaulting on its obligations.

“It has always been the case that these talks would proceed to a point where the remaining areas of disagreement would be addressed by leaders and the president,” White House press secretary Jay Carney told reporters.

He said the Biden talks “may or may not resume” and that he had nothing to announce on the next steps.

Senate Majority Leader Harry Reid, D-Nev., said it appeared that Republicans were “giving up” on the talks.

“It’s in the hands of the speaker and the president and sadly, probably me,” Reid said, referring to House Speaker John Boehner, R-Ohio. Reid said he hadn’t been invited to any meetings on the deficit.

“The Democrats continue to insist that any deal must include tax increases,” Cantor, R-Virginia, said in a statement announcing his decision. “There is not support in the House for a tax increase.”

“If we are going to meet the president’s timetable to come to an agreement at the end of this month,” Obama “has to engage,” Boehner told reporters. “I would expect to hear from him.”

Senate Finance Committee Chairman Max Baucus of Montana, one of the Democratic negotiators, said talks can’t continue without the Republicans because “You need bipartisan support to get a durable deal.”