The European Union braced on Friday to receive a letter from U.S. President Donald Trump, outlining planned duties on his largest trade and investment partner after a broadening of his tariff war in recent days.

President Trump announced on social media that he is levying 30% tariffs against Mexico and the European Union. They are set to begin on August 1.

Shelving the plan could help EU persuade the U.S. to give it a more favorable trade deal and comes just two months after the Commission suggested it.

A senior German politician said on Sunday the European Union and Washington could negotiate further and postpone higher import duties after U.S. President Donald Trump ramped up the trade war by threatening a hike in tariffs on the bloc.

President Trump sent tariff letters to more than 20 countries urging them to reach trade deals with the U.S. by Aug. 1, further escalating threats to partners including Canada. Trump also announced a 50% tariff on copper imports.

Trump insiders maintain that it would make little sense — politically or from a policy standpoint — for the president to offer any further extensions on trade.

President Donald Trump on Saturday threatened to impose a 30% tariff on imports from Mexico and the European Union starting on August 1, after weeks of negotiations with the key U.S. allies and top trading partners failed to reach a comprehensive trade deal.