Another shot has been fired in the ongoing negotiations between President Obama and Republican Congressional leaders to raise the nation's debt limit before the August 2 deadline. Obama challenged Republicans in a press conference on Monday, saying that it was time for the GOP to back up rhetoric about tackling the country's long-term debt problems. Republicans leaders have said they will seek a smaller deal with more cuts to social program and no tax increases on the wealthy. Lawmakers will return to the White House for more negotiations this afternoon. Washington correspondent Todd Zwillich and  Louise Story, Wall Street reporter for our partner,  The  New York Times, have the latest developments.