Trump retaliates by raising tariffs on Canadian steel and aluminum by 50%

On the 11th (local time), US President Trump announced that he had instructed his administration to raise tariffs on Canadian steel and aluminum imports by an additional 25%, bringing the total to 50%.
On the same day, President Trump posted on his social media account, True Social, "The province of Ontario in Canada has imposed a 25% tariff (surcharge) on electricity entering the United States.
"I have directed the Secretary of Commerce to impose an additional 25 percent tariff, raising the total tariff on all steel and aluminum entering the United States from Canada to 50 percent."
He added that "Canada has some of the highest tariffs in the world" and that "the measures will come into effect on the 12th."
Ontario Premier Doug Ford has threatened to impose tariffs on electricity shipped to the U.S. in retaliation for President Trump's 25% tariffs on Canadian imports.
President Trump continued to attack Canada's tariffs, saying, "Canada has imposed tariffs of 250 to 390 percent on U.S. dairy products."
"We must immediately eliminate U.S. agricultural tariffs, which have long been viewed as unreasonable," he said. "I will soon declare a national electricity emergency, which will allow the U.S. to provide electricity to Canada.
"We will swiftly resolve these unjust threats," he said. He also threatened to significantly raise tariffs on automobiles. "I want Canada to eliminate the unreasonable tariffs that have been in place for so long," he said.
If not, I will significantly increase tariffs on autos starting April 2nd," he said. "This will effectively permanently destroy Canada's auto manufacturing industry."
After President Trump announced the additional tariffs, the New York stock market, which had been rising, suddenly fell. The market was shaken by the impact of President Trump's tariffs and fears of an economic recession.
This is the situation.