Beijing's tariff retaliation was delivered with strategic timing, hours before an important address by Powell, and as Trump prepared to depart for the G-7 meeting in Biarritz.
"My only question is, who is our bigger enemy, Jay Powel (sic) or Chairman Xi?" - a reference to Xi Jinping.
Moments later, he demanded American companies cut ties with China.
"We don't need China and frankly, would be far better off without them", he said in his tweets.
Meanwhile, China has already fired back with Global Times editor Hu Xijin saying Trump is s welcome to relocate GM, Ford and other automakers back to the US.
These last set of tariffs were supposed to go in effect on 1 September but Trump delayed them to 15 December to avoid the popular holiday shopping season. "Escalating tensions is not good for market stability, investor confidence or American jobs". The Dow Jones Industrial Average closed down 643 points - before Trump announced the new tariffs.
But the promise of future dangers remained.
China's announcement Friday that it was raising tariffs on $75 billion in US imports sent Trump into a rage and White House aides scrambling for a response.
He also said planned tariffs on $300b ($NZ468.4) of other Chinese goods will now be 15 percent instead of 10 percent. "I think the way China is reacting to this whole thing is simply reinforcing America's perception of China as a bad actor". "China was forced to take countermeasures".
U.S. officials would need to weigh the impact of China's likely retaliation and how United States companies would be affected. "I'm completely surprised by it", said Alison Acosta Winters, senior policy fellow at Americans for Prosperity, a conservative group.
Given Trump's record as a global outlier on issues of trade, climate change and confronting Iran, and his propensity for derailing worldwide confabs with threats and occasionally bellicose rhetoric, diplomats here hope to make progress on the margins, if at all, at sessions in the picturesque seaside town on France's Basque coast.
Trump also said on Twitter on Friday that the economy was "strong and good", while "the rest of the world is not doing so well".
Administration officials, including US Trade Representative Robert Lighthizer and adviser Peter Navarro discussed potential retaliatory options.
Some of the Chinese countermeasures will take effect starting September 1, while the rest will come into effect from December 15, according to the announcement from China's Finance Ministry.
Experts said tax policy changes and sanctions could be used to restrict or reduce United States business activity in China, but it would take years to disentangle the world's two largest economies.
"The global growth outlook has been deteriorating since the middle of a year ago".
"When I looked up to the sky and jokingly said 'I am the chosen one, ' at a press conference two days ago, referring to taking on Trade with China, little did I realize that the media would claim that I had a 'Messiah complex, '" Trump tweeted.
"While monetary policy is a powerful tool that works to support consumer spending, business investment and public confidence, it can not provide a settled rule book for worldwide trade", Powell said.