European credit ratings agency Scope has warned that the United States could be downgraded if a lengthy trade war erodes long-term trust in the dollar, or if President Donald Trump implements even more extreme measures such as capital controls.

Beijing expressed weariness with the repeated rounds of increases that threaten to make much of the trade between the world’s two biggest economies grind to a halt.

Beijing announced a new round of 50 percent tariffs in response to President Trump’s latest levies as the trade conflict between the superpowers escalates.