President Donald Trump unveiled the first in a wave of promised letters that threaten to impose higher tariff rates on key trading partners, but suggested that he was still open to additional negotiations and pushed off increased duties until at least Aug.

President Donald Trump cranked up the pressure Monday on America’s trading partners, firing off letters to heads of several countries, informing them of their new tariff rate. But at the same time, Trump took some of the edge off by signing an executive action Monday to extend the date for all “reciprocal” tariffs,