"It is clear that if the Americans maintain the tariff hikes, as President Trump announced, the EU will do the same," Lombard said on the sidelines of the G20 finance ministers meeting in Cape Town.
"Even if it is not in the general interest, we too must protect our interests and the interests of the countries of the Union," Lombard said.
Trump threatened Wednesday to impose 25 percent tariffs on goods imported from the European Union as frictions soared between Washington and its European allies.
Diplomats from the G7 countries spoke to US Secretary of the Treasury Scott Bessent Thursday morning, telling him that "tariff wars lead to inflation, lower growth and are not a solution", Lombard said.
Bessent did not travel to Cape Town for the G20 talks, but attended the G7 meeting virtually.
"Minister Bessent told us that negotiations would start on April 2," Lombard said, adding the EU would "represent the European countries with the aim of reaching a fair agreement".