China has underestimated President Donald Trump's resolve to move forward with tariffs unless Beijing changes its "predatory" trade practices, a top U.S. trade adviser said on Tuesday, in comments that diminished the chances of a negotiated settlement to a looming trade war between the world's economic superpowers.

The growing U.S. trade conflict with China hit financial markets hard, and Beijing vowed a firm response. It accused the United States of "extreme pressure and blackmailing" and vowed to retaliate after Trump on Monday threatened to slap a 10 percent tariff on $200 billion of Chinese goods in addition to the import duties previously announced on $50 billion in goods.

White House trade adviser Peter Navarro, who views China as a rival economic and military power, said Beijing had more to lose from a trade war. With Trump's latest salvo, he has now threatened tariffs on up to $450 billion in China's exports, out of a total of just over $500 billion in goods sold to the United States.