By Stephen Culp NEW YORK (Reuters) – Wall Street closed lower on Monday, with stocks extending their slide after U.S. Federal Reserve Chairman Jerome Powell hinted at a more aggressive tightening of monetary policy than previously anticipated, adding to uncertainties regarding the Russian invasion of Ukraine. While all three major U.S. stock indexes ended well off session lows, they snapped four-session winning streaks on the heels of their biggest weekly percentage gains since early November 2020. The central bank must move “expeditiously” to combat inflation, Powell told the National Associa…