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.

The US president and his top advisers say he could extend the time for deal making, but they insist the administration is applying maximum pressure on other nations.

The United States is close to finalizing several trade agreements in the coming days and will notify other countries of higher tariff rates by July 9, U.S. President Donald Trump said on Sunday, with the higher rates scheduled to take effect on August 1.