Reuters report

The EU is considering applying 25% taiffs on imports of around $3.5 billion of US goods if the President follows through on his plan to apply global duties to steel and aluminum imports, according to a Reuters report that cites EU sources.

The EU would mount a WTO challenge and use measures to prevent steel that had been destined for the US being dumped in the EU.

A further counter-measure under consideration would specifically target the US.

There is no word on what the measures would look like or where they would target.