A trade policy expert explains why Trump and Xi should refrain from a trade war and how they can strike a bigger deal.

Trump, who imposed a wave of tariffs on China in his first term, has slapped another 20% duty on a wide swath of Chinese goods this year. Beijing, the top buyer of American agricultural products, recently imposed retaliatory tariffs of 10% to 15% on a range of U.S. exports like chicken, corn, soybeans and beef.

The leaders of both Canada and Mexico got on the phone with President Donald Trump this past week to seek solutions after he slapped tariffs on their countries, but China’s president appears unlikely to make a similar call soon.