The Fed is scheduled to release its rates decision at 2:00 p.m. ET (6:00 p.m. GMT) at the end of a two-day policy meeting.
Also in focus is Canada's GDP and producer prices data, due at 8:30 a.m. ET.
September futures on the S&P/TSX index were up 0.03% at 7:00 a.m. ET.
The Toronto Stock Exchange's S&P/TSX fell 26.12 points, or 0.16 percent, to 16,466.05 on Tuesday.
Dow Jones Industrial Average e-mini futures were up 0.22% at 7:00 a.m. ET, while S&P 500 e-mini futures were up 0.15% and Nasdaq 100 e-mini futures were up 0.32%.
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The Trump administration said on Tuesday it would lift an Obama-era restriction on the world's biggest undeveloped gold and copper resource owned by Northern Dynasty Minerals Ltd .
Ontario Power Generation Inc said on Tuesday its unit had entered a deal with affiliates of pipeline company TC Energy Corp to buy three natural gas-fired plants in Ontario for about C$2.87 billion.
US Vice President Mike Pence on Tuesday said that a new US-Mexico-Canada trade deal needs to be approved without delay, but Democrats and organized labor said certain provisions must first be improved.