Treasurys rallied overnight, with the 10-year yield touching 2.997 percent; the rate was last seen at 3.043 percent at 2:24 p.m. ET. The yield on the 30-year Treasury bond rose to 3.339 percent and the 2-year inched higher to 2.813 percent. Bond yields move inversely to prices.
In Powell's speech on Wednesday he said that he sees the Fed's benchmark interest rate to be near to a neutral level; which marks a change from comments made in previous months. He also said that the Fed's policymaking arm is not on a preset hiking path and could adjust its plans as needed.
In October, the Fed chair stated that the U.S. was a "long way" from hitting neutral, when it came to interest rates — which suggested to markets that more rate hikes were on the horizon. Following Powell's comments on Wednesday, short-term Treasury yields came under pressure.
"Interest rates are still low by historical standards, and they remain just below the broad range of estimates of the level that would be neutral for the economy — that is, neither speeding up nor slowing down growth," Powell told the Economic Club of New York.
Powell's address followed that of Fed Vice Chair Richard Clarida, who on Tuesday said that interest rates are "much closer" to a level that neither stimulates nor restricts growth.
A growing number of central bank officials, including Powell and Clarida, have emphasized the importance of the Fed's reliance on financial data when considering further increases to the federal funds rate. Weakness in financial markets — both in the U.S. and overseas — have led some investors to wonder whether Fed members may temper the pace of their rates hikes.
Tepid inflation, a plunge in oil prices and subsiding effects from President Donald Trump's tax cuts have also added to concerns that the robust economic growth in the U.S. over the past year may be coming to a end. That could influence Fed policymakers, who may be less apt to hike borrowing costs if gross domestic product growth slows.
"We see two tightenings at most in 2019 and then they'll stop," Krishna Memani, chief investment officer at OppenheimerFunds, said on "Squawk Box" on Thursday. "When the stimulus fades and the tightening that they've already done kind of manifests itself in the real economy, things are going to be a lot lower from a growth standpoint than where they are right now and inflationary pressures are going to abate."
Minutes from the Fed latest meeting showed members planning on another interest rate hike in December, but a bit more cautious about U.S. trade relations and increasing amounts of debt.
Notes released Wednesday from the Nov. 7-8 meeting of the Federal Open Market Committee, which sets interest rates, indicated that the body is likely to bump the federal funds rate for a fourth and final time for the year next month. The overnight rate is currently 2.25 percent.
The personal consumption expenditures price index, the Fed's preferred inflation gauge was at 2 percent in September.
Elsewhere, trade continues to be of key importance to markets, especially with the leaders of both China and the U.S. heading to a G-20 summit in Argentina this Friday and Saturday.
—CNBC's Jeff Cox contributed to this report