Treasury Secretary Janet Yellen reinforced her warning to Congress that it has only a little time left to address the debt ceiling before the nation defaults on its obligations.

It is "highly likely" that the agency will not be able to pay all of its bills in full and on time as soon as June 1, Yellen wrote in a letter to House Speaker Kevin McCarthy on Monday.

"With an additional week of information now available, I am writing to note that we estimate that it is highly likely that Treasury will no longer be able to satisfy all of the government's obligations if Congress has not acted to raise or suspend the debt limit by early June, and potentially as early as June 1," she wrote.

This story is breaking and will be updated.