"It's been an assault".
Republicans have been counting on Trump's landmark tax reform to counter this - the United States economy has been growing at a strong rate, and big companies like Apple and Walmart responded to the tax cuts by offering bonuses to their workers and announcing new investment. Meanwhile, Trump's chief economic adviser Gary Cohn, one of the fiercest free trade advocates in the administration, resigned on Tuesday - a strong sign that the ideological isolationists in the White House are winning.
A few congressional GOP members have attempted to change the president's mind on the tariffs, including Sen. "And that's going to stop".
The president has invited "any country with which we have a security relationship" to discuss "alternative ways" to address the security risks of steel and aluminum imports, a process that could lead to other countries being excluded, according to official proclamations Trump signed at the White House.
This is why Pence, at the same time as giving speeches supporting Trump, is reportedly working behind the scenes as a liaison for pro-trade Republicans.
Experts predict other countries will use the same rationale to justify their own barriers.
The White House said Wednesday that Mexico, Canada and other countries may be spared from tariffs under national security "carve-outs".
Senator Jeff Flake, who has clashed with the White House before on other issues, strongly condemned Trump's tariff implementation, saying that "Congress can not be complicit as the administration courts economic disaster" and vowing to introduce legislation that would nullify the tariffs.
"A tariff is a tax, plain and simple", said Matthew Shay, president and CEO of the NRF. The stock market, too, is showing signs of worry over the repercussions of a potential trade war.
Sen. Jeff Flake of Arizona says, "Congress can not be complicit as the administration courts economic disaster". It eliminated numerous pre-existing tariffs affecting trade.
"We are relieved because the threat was enormous", said Yves-Thomas Dorval, the president of Conseil du patronat du Québec, a major employers group that promotes business interests in Quebec. "I'm excited about that". "That Canada could be seen as a threat to USA security is inconceivable", she said.
The dispute has fueled concerns that soybeans, the United States' most valuable export to the world's second largest economy, might be caught up in the trade actions after Beijing launched a probe into imports of US sorghum, a grain used in animal feed and liquor.
"The sweeping tariffs announced today are like dropping a bomb on a flea", he said in a statement.
However, as NPR's Anthony Kuhn notes, "Despite China's objections, the tariffs are not likely to do it much damage, since less than 2 percent of China's steel exports go to the U.S".
He also hinted that security concerns were key to the introduction of tariffs. Trump signed an executive order on January 23 which pulled the United States out of the Trans-Pacific Partnership, fulfilling his anti-Free Trade "America First" electoral pledge.
China will make a necessary response in the event of a trade war with the United States, Foreign Minister Wang Yi said on Thursday, while warning that such a war would only harm all sides. "It is distressing to see President Trump's chaotic roll-out needlessly maximizing the collateral damage to American workers, consumers and our global alliances".
Marie Lapointe, the head of the AluQuebec, said manufacturers in the US like General Motors, Ford and Toyota rely on Quebec suppliers to meet their aluminum needs. We will need to see if the European Union follows through with action.
"If you now start making concessions on other things, you give in to blackmail", said Guntram Wolff, the director of Bruegel, a research organization in Brussels.
USA steel- and aluminum-consuming industries sharply criticized the tariffs as damaging them with higher costs. John Kennedy, R-Louisiana, believes that the tariffs may even out the global playing field.
"I'm delivering on a promise I made during the campaign", Trump said.