US negotiators failed to reach a deal on the tariffs with EU counterparts ahead of a Friday deadline, the Wall Street Journal reported on Wednesday citing people familiar with the situation.
In March, the Trump administration imposed 10 percent tariffs on imported steel and 25 percent aluminum. The European Union was granted temporary exemption due to expire on Friday. However, the bloc insisted that it should be permanently exempted from them.
"If tariffs are imposed, I fear we will exercise our right under the World Trade Organization (WTO) to have rebalancing tariffs," O’Sullivan told a meeting at the Woodrow Wilson Center. "We really don't understand the logic of this."
"We are not happy with the prospect of tariffs on steel on and aluminum. We feel it is not legitimate to export additional tariffs on legitimate European exports of steel and aluminum… They're not even produced here [in the United States] in many cases," O’Sullivan said.
Earlier on Wednesday, French Finance Minister Bruno Le Maire warned that if the European Union was attacked by the proposed US tariffs, the bloc would have to act to defend its own interests.