Brussels has prepared a list of USA products to hit with countermeasures if its exports are affected by the tariffs, but says it hopes to join Canada and Mexico in being exempted.
European Commission chief Jean-Claude Juncker on Friday threatened to hit big-name United States brands such as Harley Davidson motorbikes and Levi's jeans with import duties, prompting Trump to fire back a threat to tax cars from the EU.
The EU insists that it is committed to open, global trade.
Japan's trade minister sought an exemption from USA import tariffs on steel and aluminium on Saturday (March 10) and called for "calm-headed behaviour" in a dispute that threatens to spiral into a trade war.
US Commerce Secretary Wilbur Ross appeared to give some hope for resolution on Wednesday, telling the CNBC cable network that Washington did not want a trade war.
"So we need to increase steel tariff to the extent that major producers see no benefit in trying to penetrate into the Iranian market", he said.
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". "We work together. We can not possibly be a threat to national security in the USA, so we are counting on being excluded", she said.
This shed light Trump's attacks against Germany - the biggest economy in the European Union - that have accused Berlin of contributing much less than the U.S. towards the funding of North Atlantic Treaty Organisation.
"It is not crystal clear what the president said yesterday, so we will have to seek further clarity on that", said the EU's Trade Commissioner Cecilia Malmstrom.
Malmstrom told reporters the European Union was ready to complain to the World Trade Organisation, and retaliate within 90 days.
Minister Hiroshige Seko told a news conference his USA counterpart Robert Lighthizer had only explained the schedule and procedure of the United States actions in talks in Brussels.
Malmstrom won support from German Chancellor Angela Merkel.
"We're not looking for a trade war", Ross said.
Beijing vowed to "firmly defend its legitimate rights and interests".
The Chinese Commerce Ministry called Trump's tariffs "a serious attack on normal global trade order" and said that Beijing is "firmly opposed" to the measures.
Europe exports around 5 billion euros' (R73.6-billion) worth of steel and a billion euros' worth of aluminium to the USA each year, and the commission estimates Trump's tariffs could cost some 2.8 billion euros. Trump has championed coal exports as demand from power firms at home weakens. We understand why Canadians are concerned with the NAFTA renegotiations. It's also the third largest exporter of steel to the USA, accounting for about 10% of U.S. imports of the metal by volume, according to S&P Global Platts. "We should prevent a trade war situation from excessive protectionism, in which the entire world harms each other", trade minister Paik Un-gyu told a meeting with steelmakers.
Tamny states the tariff plan is meant to protect a minimal amount of jobs in the USA while making consumers pay more.