Treasury secretary Janet Yellen, in one of her final major acts in office, warned Congress late Friday that the Treasury will need to begin "extraordinary measures" on Tuesday to avoid hitting the debt limit.

Janet L. Yellen, the outgoing Treasury secretary, urged lawmakers to raise the debt limit and protect the full faith and credit of the United States.

The US Treasury Department says it will take "extraordinary measures" from January 21, so that government debt will not exceed the limit set by law.