President Donald Trump is threatening to impose higher tariffs on Japanese exports to the United States over what he claims is the country’s unwillingness to buy American-grown rice.

Japan will not sacrifice the agricultural sector as part of its tariff talks with the United States, its top negotiator said on Tuesday, after President Donald Trump complained that the key Asian ally was not buying American rice.

The Trump administration has been narrowing its focus to America’s 18 largest trading partners, and as the deadline approaches to reinstate the president’s “Liberation Day”