As talks with Beijing over China's trade practices dragged on last month, Treasury Secretary Steve Mnuchin appeared on Fox News with word of some progress.
On Thursday, Prime Minister Justin Trudeau said the steel and aluminum tariffs were "totally unacceptable".
"This was the G7", said Mnuchin.
The president took to Twitter on Saturday to defend his aggressive trade policies.
Liam Fox has condemned Donald Trump's steel and aluminium tariffs as "patently absurd" but has insisted the President's "protectionism" and apparent disregard for the United Kingdom economy will not affect a post-Brexit trade deal. He soon suggested he might exempt certain countries from them.
"This doesn't happen that often at G7 meetings, but it was the US against everyone else", Aso told reporters.
The U.S. imposed the tariffs in March, but gave Canada and the European Union - the biggest sources of foreign aluminum and steel for the U.S. - a grace period that ended at midnight Thursday. He blames what he calls their abusive trade policies for America's persistent trade deficits - $566 billion a year ago.
Canadian Prime Minister Justin Trudeau has said the USA move is "totally unacceptable". But earlier this year he said he mused about rejoining the agreement.
Former trade minister Francis Maude, now Lord Maude of Horsham, condemned the tariffs as "stupid and counterproductive".
Washington had granted Canada and Mexico an exemption on the metals tariffs to give the parties time to successfully renegotiate the 1994 continental trade pact. "The problem is, if there's a signal there, it's pretty weak", Ikenson says.
Protecting technology is the key issue in the USA trade dispute with China, which the White House said will face 25% tariffs on $50 billion in goods.
Larry Kudlow, director of the National Economic Council, tells reporters Friday that he remains optimistic about the outcome of negotiations with Canada, Europe and Mexico in spite of recent escalations.
Antonio Tajani, president of the European Parliament, said the European Union "will respond with all available tools to defend our interests". Mr Trump has also complained about barriers United States firms face in Europe and elsewhere. The president has frequently suggested he sees sowing confusion as an essential part of keeping adversaries on guard.
His cabinet colleague Luis Videgaray, the secretary of foreign affairs, said Mexico "has its limits" but its position on various themes in which it cooperates with the US will not change because of "offensive rhetoric or unjustified measures" such as the tariffs.
"It is a spectacular decision which is causing a lot of noise for nothing because ultimately this will not re-balance U.S. trade, it will weaken growth and kill jobs", he said. "This is a very strong Canadian action in response to a very bad USA decision".
Brussels has lodged an eight-page list at the World Trade Organization of goods it would hit with retaliatory measures.
For example, the Commerce Department barred the Chinese telecom company ZTE from buying parts in the US, because it had violated sanctions against North Korea and Iran.
Mexico said it would penalize US imports including flat steel, cheese, fruits, pork bellies and sausage.
He said: "I am sure that there are chips on both sides that can get traded to make the problem go away".
Such confusion over goals also undermines people's faith in the notion that the global trading system is fair, Drake adds. "Without a strong economy you can't have strong national security", Ross said.