South Korea's acting President Choi Sang-mok on Wednesday ordered a review into the impact of U.S. tariffs on Canada, Mexico and China that came into force this week.Choi also ordered support measures to be prepared for domestic firms operating businesses in those countries and to be ready for consultations with the U.

South Korean firms with businesses in Canada and Mexico revealed that they are bracing for U.S. President Donald Trump’s tariff threats.

South Korea's Acting President Choi Sang-mok said on Tuesday that the government, parliament and the private sector should be united to respond to the U.S. "trade war".

U.S. President Donald Trump has criticized South Korea for imposing more unfair tariffs on American products than China. The President also criticized the country for issuing subsidies to foreign chipmakers like Samsung Electronics Co.