Avoiding the "sequester" is "round three" in the debt-reduction debate, former Clinton Treasury Secretary Lawrence Summers told CNBC Tuesday, arguing for a "balanced approach" because President Barack Obama has agreed to more spending cuts than revenue during the process.

In a "Squawk Box" interview, Summers said the funding constraints of the Budget Control Act of 2011 — which resolved that year's debt ceiling crisis — were round one. "You had spending cuts that were far larger from the discretionary side, that were far larger than anything [on revenue] that happened in December. Right now, we're way in balance toward more spending cuts."