BRUSSELS, March 12 (Xinhua) -- The European Commission said on Thursday it would respond "firmly and proportionately" to any breach of commitments under the European Union (EU)-U.S. trade deal, following Washington's launch of a Section 301 investigation into 16 economic entities, including the EU.

European Commission Deputy Chief Spokesperson Olof Gill told a press briefing that the Commission would carefully review the details of the U.S. investigation and continue to ensure that the EU's interests are fully protected.

Gill added that the Commission would seek further clarification from Washington on how the Section 301 investigation would interact with the framework agreed under the EU-U.S. joint statement.

"The Commission will respond firmly and proportionately to any breach of the joint statement commitments," Gill said.

Under the EU-U.S. trade deal reached in July last year, the EU agreed to eliminate tariffs on all U.S. industrial products and introduce tariff-rate quotas for a wide range of U.S. agri-food products entering the EU market. In return, Washington would set a 15-percent tariff ceiling on most EU goods exported to the United States.