Massive US tariffs have come into force as condemnation of the Trump administration's move intensifies.
Criticism of the import tax on steel and aluminium from the EU, Canada and Mexico was joined by top Republicans.
Leaders from affected nations reacted furiously, setting out tit-for-tat tariffs on the US, ranging from steel to sleeping bags and ballpoint pens.
French President Emmanuel Macron told Mr Trump by phone that the US move was "illegal".
Mr Macron told him the EU would respond in a "firm and proportionate manner", the Elysee Palace says.
The French president normally enjoys a good relationship with his US counterpart.
Mr Trump has justified the tariffs, which came into force on Friday, by arguing that US steel and aluminium producers are vital to national security and threatened by a global supply glut.