The Fed is dealing with competing macroeconomic forces that could tie its hands and leave Powell and the central bank behind the curve, JPMorgan said.

U.S. stock index futures fell on Monday after President Donald Trump reignited concerns about the effects of a global trade war by introducing new tariffs, while markets awaited the Federal Reserve's monetary policy decision this week.

Fed Chairman Jerome Powell will talk to reporters Wednesday as Trump deems him a “major loser” and a “total stiff.”

Fed Chairman Jerome Powell will talk to reporters Wednesday as Trump deems him a “major loser” and a “total stiff.”

The Federal Reserve will almost certainly leave its key rate unchanged at about 4.3 percent when it meets Tuesday and Wednesday.

President Trump’s trade war had, until Sunday night, centered on goods — cars, toys, food, clothes, the tangible stuff we put in and out of virtual and physical shopping carts.

Wall Street's main indexes opened lower on Monday after President Donald Trump rekindled worries about the ramifications of a global trade war by introducing new tariffs, while focus remained on the Fed's monetary policy decision later this week.