US equity futures were falling ahead of Tuesday's opening bell as traders monitored the potential impact of US President Donald Trump's tariffs on Canada, Mexico and China.

The Dow Jones Industrial Average futures slipped 0.2%, S&P 500 futures declined 0.7%, and Nasdaq futures were down 0.8%.

Trump's new tariffs on the country's top three trading partners took effect Tuesday. China already responded with retaliatory tariffs, while Canada and Mexico are also expected to unveil similar moves, according to media reports.

Oil prices were lower, with front-month global benchmark North Sea Brent crude down 1.5% at $70.53 per barrel and US West Texas Intermediate crude 1.2% lower at $67.54 per barrel.

On the light economic calendar, New York Federal Reserve President John Williams speaks at 2:20 pm ET.

In other world markets, Japan's Nikkei closed 1.2% lower, Hong Kong's Hang Seng ended 0.3% lower, and China's Shanghai Composite finished 0.2% higher. Meanwhile, the UK's FTSE 100 was down 0.8%, and Germany's DAX index was 2.7% lower in Europe's early afternoon session.

In equities, shares of Walgreens Boots Alliance (WBA) were 5.5% higher pre-bell after The Wall Street Journal reported overnight that the company is nearing the completion of a $10 billion go-private deal with private-equity firm Sycamore Partners. Okta (OKTA) stock was up 14%, a day after the company posted higher fiscal Q4 non-GAAP earnings and revenue in addition to saying it exceeded $1 billion in aggregate sales in the Amazon Web Services Marketplace. Sea (SE) shares were up 6.5% after the company reported it swung to Q4 earnings amid higher revenue.

On the losing side, KKR (KKR) shares were down 4% after the company launched an offering of $1.50 billion of Series D mandatory convertible preferred stock. GigaCloud Technology (GCT) stock was 19% lower, a day after the company posted lower Q4 adjusted earnings.