A U.S. decision on import tariffs on EU steel and aluminum will be announced on Thursday either before markets open or after markets close, he said.

"We don't want a trade war," Ross was quoted as saying.

"(It's) up to the European Union to decide if it wants to take retaliatory measures. The next question would be: how will the (U.S President Donald) Trump react? You saw his reaction when China decided to retaliate.

"If there is an escalation it will be because the EU would have decided to retaliate," he added.

(Reporting by Ingrid Melander; editing by John Stonestreet)