U.S. President Donald Trump will speak with Chinese President Xi Jinping as soon as this week, Trump's spokesperson said, setting up a major diplomatic exchange as the world's two largest economies seek a deal that could avert a broader trade war.

China on Tuesday slapped tariffs on U.S. imports in a swift response to new U.S. duties on Chinese goods, renewing a trade war between the world's top two economies as President Donald Trump sought to punish China for not halting the flow of illicit drugs.