U.S. President Donald Trump will speak with Chinese President Xi Jinping within the next couple of days, setting up a major diplomatic exchange as the superpowers seek a deal that could avert a broader trade war.

China has reiterated its threat to take “necessary countermeasures to defend its legitimate rights and interests” following President Donald Trump’s decision to impose 10% tariffs.

China’s Ministry of Commerce said it would file a legal case at the World Trade Organization, but signaled it still wanted a stable relationship with the U.S.