US stock futures fell on Tuesday in the wait for the Federal Reserve meeting to start, as investors gauged the impact of President Trump's tariffs on its decision making and the path of interest rates.

Shares were mostly higher early Tuesday in Asia after benchmarks fell on Wall Street, snapping a nine-day winning streak. Oil prices bounced back slightly from a 4-year low and U.S. stock futures slipped.

U.S. stock futures point to a lower open as investors wait for the outcome on Wednesday of the Federal Reserve's policy meeting and any trade deal news.

Futures tied to Canada's main stock index edged lower on Tuesday, as U.S. President Donald Trump's fresh tariff threats renewed trade war fears, while investors awaited the Federal Reserve's monetary policy decision.

Wall Street is almost certain that the Fed will keep interest rates steady in the 4.25-4.50% range, but analysts expect that Trump will ratchet up his attacks on Fed Chair Jerome Powell for not lowering rates.