Wall Street stocks fell on Wednesday as possible U.S. military action against Syria stoked investor concerns about geopolitical risk to the American economy and minutes from the Federal Open Market Committee sparked worries about a more hawkish view on interest-rate increases.

The decline followed two days of gains, driven by easing concerns about trade tensions between the United States and China.

On Wednesday, U.S. President Donald Trump warned Russia of imminent military action in Syria, declaring missiles "will be coming."

The rising tensions sent oil prices surging, boosting energy stocks 1 per cent. But the risk-off sentiment weighed on Treasury yields, pushing financial stocks down 1.3 per cent.

"There's general nervousness about what might happen with any strikes and the potential escalation of tensions with Russia," said Anwiti Bahuguna, senior portfolio manager at Columbia Threadneedle Investments in Boston.

The major Wall Street indexes edged even lower after minutes from the Federal Open Market Committee showed concern among a few of its members that rising inflation might require a faster pace of interest rate hikes than anticipated.

Members of the Federal Reserve voted unanimously to raise borrowing costs by a quarter percentage point and expressed confidence that the economy would strengthen and inflation would rise in coming months.

"The minutes were modestly negative," said John Carey, portfolio manager at Amundi Pioneer Asset Management in Boston. "People had been speculating that due to all the turbulence in the market because of geopolitical uncertainties that the Fed might consider pausing or slowing down the interest rate increases."

The Dow Jones Industrial Average fell 218.55 points, or 0.9 per cent, to 24,189.45, the S&P 500 lost 14.68 points, or 0.55 per cent, to 2,642.19 and the Nasdaq Composite dropped 25.28 points, or 0.36 per cent, to 7,069.03.

Investors said they are looking to earnings season to provide a sustained boost to U.S. stocks. Banks JPMorgan Chase & Co, Citigroup Inc and Wells Fargo & Co will report quarterly results on Friday.

Analysts expect quarterly profits for S&P 500 companies to rise 18.5 per cent from a year ago, which would be the biggest gain in seven years, according to Thomson Reuters I/B/E/S.

Industrial distributor Fastenal (FAST.O) fell 6.2 per cent after its earnings missed expectations. The stock was the biggest decliner on the S&P, followed by industry peer WW Grainger's 4.4 per cent drop.

Advancing issues outnumbered declining ones on the NYSE by a 1.03-to-1 ratio; on Nasdaq, a 1.06-to-1 ratio favored decliners.

The S&P 500 posted six new 52-week highs and two new lows; the Nasdaq Composite recorded 46 new highs and 27 new lows.

Volume on U.S. exchanges was 6.04 billion shares, compared with the 7.29 billion-share average for the full session over the last 20 trading days.

CANADIAN STOCKS

Canada's benchmark stock index was little changed on Wednesday as higher commodity prices amid geopolitical concerns boosted the shares of energy and materials companies, offsetting a decline in the heavily-weighted financials sector.

The Toronto Stock Exchange's S&P/TSX composite index closed down 4.24 points, or 0.03 per cent, at 15,257.90.

Stocks on Wall Street were pressured by possible U.S. military action against Syria and minutes from the Federal Open Market Committee that sparked worries about a more hawkish view on interest-rate increases.

The TSX's financials group, which accounts for more than one-third of the weight of the index, fell 0.8 per cent.

Six of the index's 10 main industry groups ended lower.

The energy group climbed 1.8 per cent, while the materials group, which includes precious and base metals miners and fertilizer companies, added 0.8 per cent.

U.S. crude oil futures settled 2 per cent higher at $66.82 a barrel after Saudi Arabia said it intercepted missiles over Riyadh. Conflict in the region triggers concern about crude flows across the wider Middle East.

Gold futures rose 0.7 per cent to $1,351.7 an ounce as investors bought safe-haven assets.

The TSX posted five new 52-week highs and seven new lows.

The largest percentage gainer on the TSX was Torex Gold Resources Inc (TXG.TO), which rose 20.1 per cent, while the largest decliner was Prometic Life Sciences (PLI.TO), down 7.1 per cent.