US stocks came under pressure on Wednesday as investors waited for the Federal Reserve's decision on interest rates and clues about its future monetary policy, while a profit warning by FedEx weighed on sentiment.

The package delivery company's shares tumbled 13.6% and were on course for their sharpest one-day percentage drop since the financial crisis after FedEx blamed US-China trade tensions and a split with Amazon for its dismal full-year profit forecast.

The Dow Jones fell 71 points (0.3%) at 6.15pm to 27,038, and the Nasdaq Composite dropped 39 points (0.5%) to 7849.

In Europe, London's FTSE index closed 6 points lower (0.09%) to stand at 7.314, while the Paris CAC gained five points (0.1%) to 5,620 and the Frankfurt DAX inched 8 points higher (0.07%) to reach 12,389.

Dublin's ISEQ index slipped 35 points (0.6%) to close at 6,071. Shares in Bank of Ireland were down 3.5% to €3.49, while Glanbia slipped 0.6% to €11.23. Ryanair shares dropped 1.3% to €9.94 while Applegreen lost 2.7% to stand at €5.06 ahead of its half yearly results on Friday morning. 

Earlier in Asian trade, Tokyo's Nikkei index closed 41 points (0.2%) lower at 21,961 with investors cashing in on recent gains after a 10-day winning streak. The Hang Seng index in Hong Kong fell 36 points (0.13%) to finish at 26,754 -  extending a sell-off to a third day as traders fret over the impact of protests on the city.