Federal Reserve Chairman Jerome Powell still sees interest rate hikes coming, but noted Wednesday that the Russia-Ukraine war has injected uncertainty into the outlook.

In remarks prepared for dual appearances this week before House and Senate committees in Congress, the central bank chief acknowledged the “tremendous hardship” the Russian invasion of Ukraine is causing.

“The implications for the U.S. economy are highly uncertain, and we will be monitoring the situation closely,” Powell said.

“The near-term effects on the U.S. economy of the invasion of Ukraine, the ongoing war, the sanctions, and of events to come, remain highly uncertain,” he added. “Making appropriate monetary policy in this environment requires a recognition that the economy evolves in unexpected ways. We will need to be nimble in responding to incoming data and the evolving outlook.”

The remarks come amid 40-year highs for inflation in the U.S., complicated by a Ukraine war that has driven oil prices to around their highest levels in a decade. Consumer prices increased 7.5% from a year ago in January, and the Fed’s preferred inflation gauge showed its strongest 12-month gain since 1983.

Powell and his fellow policymakers have been indicating for weeks that they plan to start raising benchmark interest rates to tackle inflation. He reiterated the stance Wednesday that the process will involve “interest rate increases,” along with indications that the Fed eventually will start reducing its bond holdings.

“We will use our policy tools as appropriate to prevent higher inflation from becoming entrenched while promoting a sustainable expansion and a strong labor market,” he said. “We have phased out our net asset purchases. With inflation well above 2 percent and a strong labor market, we expect it will be appropriate to raise the target range for the federal funds rate at our meeting later this month.”

The Fed will start cutting the size of its asset holdings after rate hikes have begun, he added.

Since the beginning of the Covid pandemic, the Fed has been buying Treasurys and mortgage-backed securities at the fastest pace ever, driving the total holdings on the central bank balance sheet to nearly $9 trillion.

Powell said the reduction will be conducted “in a predictable manner,” largely through allowing some proceeds from the bonds to roll off each month rather than reinvesting them.

On the economy, the chairman said he still expects inflation to decelerate through the year as supply chain issues are resolved. He called the labor market “extremely tight” and noted strong wage gains, particularly for lower earners and minorities.

“We understand that high inflation imposes significant hardship, especially on those least able to meet the higher costs of essentials like food, housing, and transportation,” he said. “We know that the best thing we can do to support a strong labor market is to promote a long expansion, and that is only possible in an environment of price stability.”

Markets have fully priced in a rate increase at the March 15-16 meeting but have decreased expectations for the rest of the year since the Ukraine war began, according to CME group data. Traders are now pricing in five quarter-percentage-point increases that would take the benchmark federal funds rate from its current range of 0%-0.25% to 1.25%-1.5%.