Long-dated U.S. Treasurys rose on Thursday amid news that federal officials were pushing back an auction of two-year Treasury notes because of the debt-ceiling limit.
A Treasury announcement detailing the unusual auction delay, originally expected on Tuesday, knocked the two-year note's yield to a session low of 0.596 percent.
Yields on the note, a maturity especially sensitive to Federal Reserve interest-rate shifts, were last down 3 basis points at 0.60 percent.
Other shorter-term Treasurys, including the five-year note, were also up in price. The five-year was last yielding 1.33 percent, down 2 basis points on the day.