The European Union estimates that the first wave of Donald Trump’s steel and aluminum tariffs will hit as much as €28 billion ($29.3 billion) of the bloc’s exports in what would be a massive escalation in the US president’s trade war.

European stocks have hit record highs this month, as companies have beat fourth-quarter revenue expectations, but the topic that dominates the conversation among executives in the region is U.S. tariffs.

Hoping to head off a potential trade conflict, a top European Union official stressed the importance of active engagement and fairness in trade during a four-hour meeting with Trump administration officials.