Wall Street's main indexes jumped on Wednesday, propelled by technology and financial stocks, as signs of progress in Ukraine-Russia peace talks lifted sentiment ahead of a widely expected interest rate hike by the Federal Reserve.

New talk of compromise from both Moscow and Kyiv on a status for Ukraine outside of NATO lifted hope on Wednesday for a potential breakthrough after three weeks of war.

Nine of the 11 major S&P sectors advanced, with financials, technology and consumer discretionary shares - which largely endured the selloff this year - each climbing over 2.3%.

Megacap names Apple Inc and Microsoft Corp rose 1.8% and 1.5%, respectively, powering the S&P 500 and the Nasdaq higher.

Big banks advanced 3% in anticipation of the first rate increase since 2018. Morgan Stanley led the gains with a 6.1% jump.

The Fed is seen raising interest rates by at least 25 basis points later on Wednesday, in what would be the first in a series of increases this year as it steps up the fight against stubbornly high inflation.

The policy statement is due at 2 p.m. ET (1800 GMT) and will be followed by Fed Chair Jerome Powell's news conference. Traders will be closely watching the updated quarterly economic and interest rate projections for clues on how fast rates will increase.

"The Fed in some ways was behind the curve. It gives the market a sense of comfort that the Fed is on the ball, they're going to start moving interest rates and we could get to a place where inflation begins to temper," said John Cunnison, chief investment officer at Baker Boyer in Walla Walla, Washington.

"Any good news on Ukraine is very likely to give market participants confidence that the Fed can increase rates without hurting growth."

Historical data suggests tighter monetary policy has often been accompanied by solid gains in stocks. The S&P 500 has returned an average 7.7% in the first year the Fed raises rates, according to a Deutsche Bank study of 13 hiking cycles since 1955.

At 11:45 a.m. ET, the Dow Jones Industrial Average was up 349.25 points, or 1.04%, at 33,893.59, the S&P 500 was up 65.81 points, or 1.54%, at 4,328.26, and the Nasdaq Composite was up 343.86 points, or 2.66%, at 13,292.49.

The CBOE volatility index, also known as Wall Street's fear gauge, fell to 27.54 points, its lowest level since Feb. 25.

The global mood was also buoyed by China's promise to roll out more stimulus for the economy and keep markets stable.

U.S.-listed shares of Baidu, Alibaba Group, JD.com, Tencent Music, Pinduoduo Inc and Didi Global surged between 25% and 46.4% as China's securities regulator also said it would strive to reach an agreement on China-U.S. audit supervision cooperation.

Kohl's Corp gained 13.4% after Axios reported Hudson's Bay is considering a bid for the U.S. department store operator.

Advancing issues outnumbered decliners by a 3.82-to-1 ratio on the NYSE and by a 4.11-to-1 ratio on the Nasdaq.

The S&P index recorded 15 new 52-week highs and no new lows, while the Nasdaq recorded 21 new highs and 53 new lows.