European stocks dropped to their lowest in more than three months Monday, with bank shares among decliners as investors faced heightened concerns about the Brexit vote on whether the U.K. should cut ties with the European Union.

The moves on European markets followed sharp losses across Asian stocks, with sent Japan's Nikkei Average NIK, -1.45% tumbling by 3.5%.

U.S. stocks fell for a third straight session Monday, with the S&P 500 and the Dow Jones Industrial Average finishing at their lowest close since May 24 as investors turned increasingly jittery ahead of a Federal Reserve policy meeting and a looming vote on the U.K.'s membership in the European Union.

The Dow Jones Industrial Average DJIA, -0.74% shed 132.86 points, or 0.7%, to end at 17,732.48, while the S&P 500 SPX, -0.81% slid 17.01 points, or 0.8%, to finish at 2,079.06. The tech-heavy Nasdaq Composite COMP, -0.94% was down 46.11 points, or 0.9%, to close at 4,848.44, its lowest finish since May 23.

Asian stocks slipped on Tuesday ahead of the U.S. Federal Reserve's two-day meeting that begins later in the day, amid growing worries this month's referendum in Britain could see it exit the European Union.

Uncertainty over this week's Federal Reserve policy meeting has weighed on markets, though the U.S. central bank is widely expected to leave rates unchanged after the much weaker-than-expected May nonfarm payrolls report.

The Bank of England, Swiss National Bank and the Bank of Japan will also meet this week, and are similarly expected to stand pat on policy with the Brexit vote looming.