U.S. President Donald Trump announced Monday that the United States will impose a 25 percent reciprocal tariff on all imports from South Korea starting August 1.

The announcement was made in a letter posted to his social media platform, Truth Social, in which Trump claimed that the trade relationship between the two countries has been far from “reciprocal.”

Trump said in the letter addressed to President Lee Jae Myung that the U.S. would impose a flat 25 percent tariff on all South Korean products entering the country, separate from existing sectoral tariffs.

He added that goods transshipped to evade higher tariffs will be subject to those higher rates. 

Trump warned that if South Korea responds by raising its own tariffs, the U.S. will add the same percentage increase on top of the 25 percent tariff.

However, Trump left the door open for adjustments, stating that if South Korea opens its markets and eliminates tariff and non-tariff barriers, the U.S. may consider revising the rate outlined in the letter.