The country’s new president, in office for a little over a month, had just dispatched his senior deputies to Washington to try to work out a trade deal.

In letters so far to 14 countries, including smaller exporters to the United States such as Serbia, Thailand and Tunisia, Trump hinted at opportunities for additional negotiations, even while warning that reprisals would draw a like-for-like response.

Secretary of State Marco Rubio met counterparts in Southeast Asia during his first visit to the region since taking office.

President Donald Trump announced on Monday that he is levying tariffs against South Korea and Japan beginning in August. Trump