The chair of the US Federal Reserve believed policymakers were making headway in their fight against inflation. However, Jerome Powell has abandoned some of his optimism and says they may have to take "larger steps."

On Tuesday, Powell testified before members of the Senate Banking Committee in Washington. He and his colleagues have raised interest rates repeatedly to bring the inflation rate down from more than 9 percent to 6.4. They had more recently slowed the pace of those hikes, but they may have to speed them up again.

Powell said, "The process of getting inflation back down to 2 percent has a long way to go and is likely going to be bumpy."

He pointed to some economic figures that are working against them. An unusually mild winter has encouraged consumers to spend and construction crews to get back to work. The latest jobs numbers added more pressure. The unemployment rate has fallen to 3.4 percent, its lowest level since the 1960s.

Powell says the fight against inflation is "very likely" to cost some of those jobs. He and his colleagues meet for their next Fed meeting in two weeks. He has already signaled they could raise interest rates even higher than anticipated.