WASHINGTON — Federal Reserve Chair Jerome Powell says that the appearance of a new COVID-19 variant could slow the economy and hiring, while also raising uncertainty about inflation.

The recent increase in delta cases and the emergence of the omicron variant “pose downside risks to employment and economic activity and increased uncertainty for inflation,” Powell said Monday in prepared remarks to be delivered to the Senate Banking Committee on Tuesday. The new variant could also worsen supply chain disruptions, he said.

Powell’s comments come after other Fed officials in recent weeks have said the central bank should consider winding down its ultra-low interest rate policies more quickly.