The Trump administration is stepping up pressure on trading partners to quickly make new deals before a Wednesday deadline, with plans for the United States to start sending letters Monday warning countries that higher tariffs could kick in Aug.

President Donald Trump said he had reached a trade deal with Vietnam following weeks of intense diplomacy between the nations and ahead of a deadline next week that would have seen higher tariffs imposed on the country’s imports.

“Vietnam will pay the United States a 20% Tariff on any and all goods sent into our Territory, and a 40% Tariff on any Transshipping,” Trump said on his social network. “In return, Vietnam will do something that they have never done before, give the United States of America TOTAL ACCESS to their Markets for Trade.”