Lighthizer, who campaigned with President Trump, serves as an unofficial adviser. He was reportedly passed over for Treasury secretary, but he remains close to the president. Lighthizer says U.S. trade with China has largely benefited an adversary who has engaged in stealing trade secrets and other malicious actions.

In an escalation of his trade war, President Donald Trump moved to put tariffs on nations that levy taxes and fees that hurt U.S. businesses.