Wall Street seems to be heading for a red day, with stock index futures down on Friday, as President Donald Trump slapped a 35% tariff on Canada and warned of further hikes if Ottawa retaliated. S&P 500 futures (SPX) -0.

The president revived his discredited claims about fentanyl entering the U.S. from Canada to justify his latest proposed rate of 35 percent.

Trump wrote to Carney to inform him that, from August 1, Canada will face a 35 percent import tariff after the two sides failed to reach a deal during the recent pause. The American leader said he would consider revising the 35 percent tariff "if Canada works with me to stop the flow of Fentanyl".