PARIS, March 5 (Xinhua) -- French President Emmanuel Macron on Monday urged the European Union respond swiftly in the framework of the World Trade Organization (WTO) to U.S. President Donald Trump's plan to raise tariffs on steel and aluminum imports.

Trump announced on Thursday a plan to impose penalties of 25 percent on imported steel and 10 percent on imported aluminum, a decision that has received worldwide criticism and retaliatory intentions from some of its closest allies.

"If the announcements made last week were to be confirmed and implemented, it is clear that they would violate the rules of the WTO," Macron told reporters.

"It is important in this context that the European Union reacts swiftly and proportionately within the WTO and in respect of the WTO," he added.

At a joint press meeting with Philippe Couillard, premier of the Quebec at the Elysee Palace, the French president noted that Trump's plan amouted to "economic nationalism," which according to him would lead to war and would be "a very bad response to the international environment."

For his part, Couillard said the new tariffs on steel and aluminum would impact first the " domestic American market" where consumers will pay higher prices of everything made with these metals.

"As for the trade war, it is rare that it does not make only losers. It is not a road where we must bring the world. One should rather show.. the importance of open markets and their mutual benefits," he added.