Donald Trump has repeatedly urged Xi Jinping to call him for discussions about a potential trade deal. But any off-ramp to the economic tensions will likely run through Vice Premier He Lifeng, who is Xi's Sino-American trade tsar.

The Treasury secretary said that the President Trump and Xi Jinping of China have a good relationship but that he was not aware of a call, which Mr. Trump had alluded to last week.

China’s leader Xi Jinping has released a letter denouncing tariff and trade wars and urging the multilateral trading system, stable global industrial and supply chains, and open and