Investors focus on the Fed's policy decision and Chair Jerome Powell's news conference. Earnings from Meta and Microsoft are due after the closing bell.

Starbucks stocks slipped 0.2 per cent after reporting a weaker profit than analysts expected as it tries to turn around its operations.

Volume was lower on the Nasdaq exchange while higher on the New York Stock Exchange compared with Monday, in preliminary numbers. On the Nasdaq exchange, falling stocks edged out rising ones by more than 2-to-1. In yet another rotation on the NYSE, winners slightly edged out losers.