U.S. markets are poised to open lower Wednesday ahead of congressional testimony by Federal Reserve Chair Jerome Powell, who is expected to address the central bank's response to stubborn inflation that has thrown global markets into turmoil.

Futures for the Dow Jones industrials slipped 1.2%, while S&P 500 futures fell 1.3% and oil prices tumbled more than 4%.

European benchmarks declined by midday after shares in Asia finished lower, including in Japan, Australia, South Korea and China.

Stocks have been mostly sliding in recent weeks as investors adjust to higher interest rates that the Federal Reserve and other central banks are increasingly doling out to temper record-high inflation. Investors are worried that the Fed risks slowing economic growth too much and bringing on a recession.

The Biden administration is very aware of the political risks of runaway inflation in an election year. On Wednesday, President Joe Biden will call on Congress to suspend federal gasoline and diesel taxes for three months with hopes of easing financial pressures at the pump.

Powell's appearance on Capitol Hill Wednesday is the first of two days of testimony as part of the central bank’s semi-annual monetary policy report.

“For now, the fundamental catalyst for a more sustained rebound seems fragile, with all eyes on Fed Chair Jerome Powell’s testimony ahead to further drive expectations of policy outlook and inflation,” Yeap Jun Rong, market strategist at IG in Singapore, said in a commentary.

In Europe, Germany’s DAX slumped 1.9%, France's CAC 40 lost 1.6% and Britain's FTSE 100 fell 1.1%.

Japan’s benchmark Nikkei 225 shed 0.4% to finish at 26,149.55. Australia’s S&P/ASX 200 lost 0.2% to 6,508.50. South Korea’s Kospi tumbled 2.7% to 2,342.81. Hong Kong’s Hang Seng dropped 2.6% to 21,008.34, while the Shanghai Composite sank 1.2% to 3,267.20.

Last week, the Fed hiked its key short-term interest rate by triple the usual amount. It has also just begun allowing some of the trillions of dollars of bonds it purchased through the pandemic to roll off its balance sheet. That should put upward pressure on longer-term interest rates and is another way central banks are yanking supports earlier propped underneath markets to bolster the economy.

The Fed’s moves are happening as some discouraging signals have emerged about the economy, including sagging spending at retailers and soured consumer sentiment. The Fed could consider another such mega-hike at its next meeting in July, but Powell has said increases of three-quarters of a percentage point would not be common.

The worries over inflation and interest rates have been worsened by a spike in energy prices following Russia's invasion of Ukraine. The price of U.S. crude oil is up about 52% for the year. That has taken a bigger bite out of people's wallets at the gas pump and is prompting a slowdown in spending elsewhere.

Oil prices fell back on Wednesday, with benchmark U.S. crude shedding $5.04 to $104.48 per barrel. Brent crude, the international standard, declined $4.73 to $109.92 a barrel.

In currency trading, the U.S. dollar inched down to 136.15 Japanese yen from 136.64 yen. The euro cost $1.0515, down from $1.0537.