Officials say the White House and Republican leaders in Congress are making significant progress toward a last-minute agreement to avoid a default threatened for Tuesday.
These officials say the two sides are discussing a plan to raise the debt limit by about $2.4 trillion and enact spending cuts of a slightly larger amount in two stages.
The deal under discussion would also require Congress to vote on a balanced budget amendment to the Constitution, but not require its approval.
The officials spoke on condition of anonymity, citing the sensitivity of the discussions.
Reid delayed a test vote on the Democratic debt limit increase plan until 1 p.m. Sunday, as some Senate leaders are expected to work with White House officials through the night.
The Associated Press contributed to this article.