Democratic lawmakers, however, said the concession doesn't go far enough, The Washington Post reported.
The Republicans propose increasing tax revenue by $250 billion by limiting the value of itemized deductions for the wealthy -- including some home mortgage interest and state and local taxes -- and another $40 billion by tweaking inflation adjustments. In return, Republicans want the George W. Bush-era tax cuts made permanent.
Democrats, however, want at least $1 trillion in new revenues in return for extending the Bush tax cuts.
Sen. John Kerry, D-Mass., a member of the supercommittee, said the Republicans' proposal "doesn't get the job done, and we've got some distance to travel, and we're working very hard to do that."
The Hill reported an unidentified GOP aide said Republicans were responding to Democratic proposals.
"This is not a Republican proposal," the aide said. "Why would Republicans propose increasing taxes? This is Republicans giving something in return for lowered tax rates."