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.

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

Some officials in South Korea say agreeing to the pipeline investment might placate the U.S., but Trump is still threatening tariffs.

China’s foreign ministry spokesman, Lin Jian, warns that China would fight ‘to the bitter end’ in ‘a tariff war, a trade war, or any other kind of 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.