EU foreign policy chief Federica Mogherini said Friday that the European Union would protect its interests and pledged proportionate measures to Washington's introduction of tariffs.

EU foreign policy chief Federica Mogherini on Friday said the bloc was not in a trade war with anyone but would defend its interests, hours after the US slapped punishing metals tariffs on Europe and other close allies.

The US announced that starting on 1 June 2018 it will impose additional duties of 25 % and 10 % respectively on imports of steel and aluminium from the EU.

“The European Union is not at war with anyone… the EU is a peace project, including on trade,” Mogherini said at a joint press conference in Brussels with the visiting Chinese Foreign Minister Wang Yi.

In a veiled warning, Wang warned Washington to abide its commitments to avoid a separate US-China trade war as a 50-strong US delegation held talks in Beijing.

“We always honour our words and we expect that our partners keep their word as well,” Wang said.

The Latest on the U.S. decision to impose new tariffs on European, Canadian and Mexican goods

The European Union is planning retaliatory tariffs on U.S. steel and food goods in the coming weeks, once it calculates the exact cost to European Union companies of the U.S. tariffs. Macron pledged the riposte would be "firm" and "proportionate" and in line with World Trade Organization rules.

The U.S. decision came despite last-minute talks in Paris this week to try to reach a deal.

French President Emmanuel Macron has told U.S. President Donald Trump that the new U.S. tariffs on European, Mexican and Canadian goods are illegal and a "mistake."

Macron's office said in a statement Friday that the two presidents spoke by phone after Trump's administration announced the decision Thursday to impose 25 percent tariffs on steel and 10 percent tariffs on aluminum.