"Based on updated projections, there is a scenario in September, before Congress reconvenes, "Mnuchin wrote in a letter.
Pelosi and Mnuchin have said they are trying to jumpstart the budget, and that they have come to terms with their efforts to increase their energy efficiency.
Mnuchin and Pelosi are likely to speak again Friday. Mnuchin's letter to Capitol's Hill but she knew it coming.
In his letter, Mnuchin called on Congress to restore borrowing power.