The Fed chair said it would likely be appropriate to raise rates from near zero "sometime later this year," though the decision would continue to rely on economic data.
In her comments last week, Yellen had not identified herself as part of the group favoring rate hikes this year, but she had made a similar comment during the summer.
On the data front, the final second-quarter GDP reading came in at 3.9 percent, above the expected 3.7 percent.. Consumer sentiment is due to be released at 10:00 a.m.
The yield on the benchmark 10-year Treasury note sat higher on Friday, at around 2.16 percent, after closing at 2.12 percent on Thursday. The yield on the 30-year bond was also up, at around 2.95 percent, after closing at 2.905 percent. The yield on a bond rises when its price falls.
Treasury bill yields surged earlier after surprise news that House Speaker John Boehner will resign from Congress ahead of a potential government shutdown.
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The yield for three-month Treasurys tripled in minutes, albeit from very low levels. Yields on six-month Treasurys also jumped.
Treasury bills represent government debt that matures in the very short term, and thus react to short-term fears around government funding. If the risk increases that short-term bills won't get paid off (currently seen as exceptionally unlikely), short-term yields will need to rise in order to compensate for that risk.
Thursday saw the Treasury Department auction $29 billion in seven-year notes at a high yield of 1.813 percent. The bid-to-cover ratio, an indicator of demand, was 2.51 and above the recent average of 2.45.
--CNBC's Alex Rosenberg contributed to this report