Dhaka, March 6 -- US President Donald Trump will exempt automakers from his punishing 25% tariffs on Canada and Mexico for one month as long as they comply with existing free trade rules, the White House said on Wednesday, a development that halted at least for now Wall Street's steepest skid in nearly three months.

Trump is also open to hearing about other products that should be exempted from the tariffs, which took effect Tuesday, the White House said.

But Trump made clear he was not calling off his trade war with Canada and Mexico as he pressures both countries to deter fentanyl smuggling. After a phone call with Canadian Prime Minister Justin Trudeau, Trump said he was not convinced the situation had improved.

"He said that it's g...