At the start of March, Trump imposed a 25% increase in steel tariffs and a 10% increase on aluminum.
Failing to include the national security adviser in talks on tariffs would seem highly unusual, given Trump's argument that weakened USA steel and aluminum industries would threaten national security.
However, he exempted allies, Canada and Mexico from the measure, and said the allies having "security relationship" with the United States could propose exemptions, before the new tariffs come into force.
Prime Minister of Australia Malcolm Turnbull tweeted a video on Monday saying his country has achieved a "commitment" from President Trump that his tariff plan on steel and aluminum won't apply to exports from Australia.
President TrumpDonald John TrumpAccuser says Trump should be afraid of the truth Woman behind pro-Trump Facebook page denies being influenced by Russians Shulkin says he has White House approval to root out "subversion" at VA MORE's new tariffs on steel and aluminum will hurt my farm.
"I have to say, when President Trump says he's putting tariffs on the table, I think tariffs are one part of reworking our trade policy overall", she said. If the USA is isolated, it could actually be good for Australia. Now we're probably going to lose even more.
Here in farm country, these tariffs will sting.
The EU topped the list, followed by Brazil, South Korea, China and then Japan. And Douglas Porter, chief economist at the Bank of Montreal added, "We're pretty consistently flabbergasted that Canada is at the top of the hit parade of trade villains in Trump's eyes".
I talked to people in the metal fabrication industry after Trump's initial announcement, and the response to the tariffs was negative.
Ms Bishop said the Turnbull government first got wind of the possibility of new tariffs in April 2017 and swung into action with a strong lobbying effort by ministers, officials and business contacts. "So nobody owes him anything, and that makes it a lot easier for them to retaliate".
Asked to respond to Trump's accusations that the EU is imposing barriers to US automakers, Malmstrom said that "it's hard to argue on Twitter over these issues, but the European Union is a very open market".
Michael Dolega, economist at TD Economics estimates that about 5,000 to 10,000 jobs could be added to steel and aluminum production in the USA, but there could also be a loss of 25,000 to 50,000 jobs in metal-intensive sectors like machinery and transport equipment.
"Make no mistake, if the president goes through with this, it will kill American jobs".
Republican Senators Ron Johnson (Wis.) and Cory Gardner (Colo.) both signaled support on Sunday for Flake's bill to stop the tariffs, though Johnson cautioned it would not likely get enough votes to override a presidential veto.
Jakob Hanke and Hans von der Burchard contributed to this article.