“It’s a good sign, because in a sense it shows that there is a willingness to discuss trade issues in a multilateral framework again,” Draghi told reporters in Frankfurt.

But “it’s too early to assess the actual content”, he said, warning that “the threat of protectionism” remained a “prominent” risk to eurozone growth.

Draghi has repeatedly warned that increased protectionism around the world could hurt euro area exports and undermine the eurozone economy at a time when the ECB is preparing to exit its crisis-era stimulus programme.

European capitals have cautiously welcomed the trade truce announced by Trump and Juncker after talks in Washington on Wednesday, but doubts lingered about its feasibility.

The two leaders announced a plan to defuse a lingering trade row, that in effect saw Washington back off a threat of auto tariffs against Europe for now.

But critics of the agreement said it was vague on details, and many were upset that existing steel and aluminium tariffs will remain in place.

While Chancellor Angela Merkel’s spokeswoman welcomed the “constructive” meeting, French Finance Minister Bruno Le Maire immediately demanded “clarifications” over the agreed measures.