"We hope that we can get confirmation that the EU is excluded from this", EU Trade Commissioner Cecilia Malmstroem told policy makers, experts and reporters at an event in Brussels.
Under World Trade Organisation rules, such counter-measures have to be in place within 90 days of the United States tariffs entering force.
Saturday's meetings in Brussels had been previously planned but took on greater importance because of Trump's announcement of a 25-percent tariff on steel imports and 10 percent on aluminum imports.
He said other countries could be spared if they can convince the administration that their steel and aluminum exports don't threaten American industry. "Our assumption is that the European Union is a whole body and that the US will respect that...otherwise, that is questioning the whole European Union as a project", Ms. Malmstrom told a business forum on Thursday. "No immediate clarity on the exact U.S. procedure for exemption however, so discussions will continue next week".
"If they drop their horrific barriers & tariffs on USA products going in, we will likewise drop ours". She noted that under WTO rules, once Trump's tariffs come into force in two weeks, the European Union would have 90 days to enact the measures. The country's steel industry association has said the tariffs are an "extreme" measure.
European Commission Vice President Jyrki Katainen said: "We need a dialogue with the United States". She is set to meet U.S. Trade Representative Robert Lighthizer in Brussels over the weekend.
"We are friends. We are allies".
"We are an ally, not a threat", Katainen said.
Europe's main steel federation said Trump's reasons for slapping tariffs on steel and aluminum are absurd and warned that the move could cost tens of thousands of jobs across the continent.
While carrying a message to Washington to push forward a diplomatic breakthrough over North Korea, South Korea's national security office chief Chung Eui-yong asked U.S. officials to support Seoul's request for a waiver, a presidential spokesman said.
Along with a huge range of steel products, the EU's hit list of flagship American products lined up for counter measures includes peanut butter, bourbon whiskey and denim jeans. European steel producers are concerned about a loss of market access, but also that steel from elsewhere will flood in.
British steel accounts for 1% of US steel imports, but 5% of United Kingdom steel exports by volume and 15% of it by value, largely because the exports focus on high-value products, including to the USA military, Mr. Fox said.