China warned the Trump administration on Tuesday against reigniting trade tension by restoring tariffs on its goods next month, and threatened to retaliate against nations that strike deals with the United States to cut China out of supply chains.

President Donald Trump sent out a slew of letters Wednesday to some global trading partners, advising them of tariff levels as high as 50% for their exports to the United States.

China cautioned the Trump administration against re-escalating trade tensions by re-imposing tariffs on Chinese goods next month. Beijing also threatened retaliation against countries that forge deals with the United States aimed at excluding China from supply chains.