"If the president asked you to resign, would you do it?" the moderator asked Powell.
Powell stressed Fed officials are patient and keeping a close eye on the voices of financial market, calling Fed policy as flexible and clung to real-time economic developments.
The monthly US employment report will be released at 8:30 a.m.in Washington on Friday - giving Powell two hours to digest the figures before his big appearance.
The Fed raised its benchmark interest rate four times in 2018, with the latest announced on December 19, when Powell said his institution's policy decisions are "not on a preset course". "With the muted inflation readings we have seen coming in, we will be patient as we watch to see how the economy evolves".
Powell called the December jobs report "very strong" and said US data seems "to be on track to sustain good momentum into the new year". Some analysts said investors were acting as if a recession was on the horizon, despite a lack of evidence that the US economy is struggling.
Powell's remarks reassured investors who have anxious the Fed might raise rates excessively, but Jason Schenker of Prestige Economics suggested the Fed could.
The Federal Reserve raised interest rates in December for the seventh time since Trump took office, four of which happened under Powell, and has signaled that it would consider raising rates again in 2019.
For their part, investors see the next move being a cut, according to pricing in interest rate futures contracts.
Trump has for months criticized the Fed chief for raising rates, and Bloomberg News reported December 21 that the president had discussed firing Powell.
President Trump and Democratic leaders failed to strike a deal on Friday to end a partial shutdown of the USA government as they fought over Trump's request for $5 billion to fund a wall on the border with Mexico lawmakers said.
On the economic front, stronger-than-expected employment data helped regain steam for the U.S. economy. "There aren't signs of significant economic weakness".
Dallas Fed President Robert Kaplan said on Thursday that planned rate hikes should be halted for now, while on Friday Mester said she sees only one or two rate hikes this year.
Speaking after months of volatility in world bond and stock markets, Powell avoided some of the communication missteps that in the past have roiled rather than calmed investors.
"The markets are feeling better that the Fed is not strangling the overall economy and perhaps forcing it into a recession, and that removes a monetary policy concern that has been hanging over the market for the past few months", said Robert Pavlik, chief investment strategist and senior portfolio manager at SlateStone Wealth LLC. But it has been gradually reversing that stance over the past year, although the balance sheet still remains above $4 trillion.
He added: "We're listening with sensitivity to the message that markets are sending and we're going to be taking those downside risks into account as we make policy going forward".