US equity futures were falling before Monday's opening bell ahead of the Federal Reserve's meeting to discuss interest rates.

Dow Jones Industrial Average futures were 0.6% lower, S&P 500 futures declined 0.8%, and Nasdaq futures were down 1%.

The Federal Open Market Committee is scheduled to start its two-day meeting on Tuesday.

Oil prices were lower, with front-month global benchmark North Sea Brent crude down 1.8% at $60.16 per barrel and US West Texas Intermediate crude 2.1% lower at $57.05 per barrel.

The Institute for Supply Management's Services index, scheduled for release at 10 am ET, is expected to come in at 50.2 for April versus March's 50.8, according to estimates compiled by Bloomberg.

In other world markets, Japan's Nikkei ended 1% higher, while Germany's DAX index was up 0.8% in Europe's early afternoon session. The Hong Kong, Chinese, and UK markets were closed for holiday.

In equities, shares of Shell (SHEL) were 1.7% lower pre-bell following a media report that the company is considering a potential acquisition of BP (BP).

On the winning side, Hyperscale Data (GPUS) shares were up over 130% after the company said its preliminary Q1 revenue exceeded $25 million.