US stock market futures were tending down Sunday, one day after President Donald Trump announced 25% tariffs on Canada and Mexico and 10% tariffs on China.

Stocks surrendered early gains and turned negative on Wall Street after the White House said President Donald Trump would impose promised tariffs on some key U.S. trading partners. The S&P 500 fell 0.

Global markets buckled up for a turbulent session Monday after Trump launched a trade war with sweeping tariffs on Canada, Mexico, and China.

American importers will pay a new 25 percent tax on goods from Canada and Mexico and a 10 percent levy on products from China.

Investors are bracing for a potential trade war that could hit the earnings of major companies and dent global growth. Canada and Mexico have said that they will hit back with retaliatory tariffs while China promised to respond with "corresponding countermeasures" and vowed to challenge Trump's move at the World Trade Organization.