A key policymaker at the European Central Bank (ECB) believes a trade war would have "damaging" consequences for the whole world, including the U.S.

Benoit Coeure, an executive board member at the euro zone's central bank, warned that the current rhetoric on trade could escalate and provoke severe shocks in the global economy.

"If this would move into a full-fledged trade war, this has a potential to have quite damaging consequences for growth and jobs, globally, including in the U.S.," he said.

Speaking to CNBC's Steve Sedgwick on the sidelines of the European House Ambrosetti Forum in Italy Friday, he said he wasn't sure that the world was in a trade war just yet.

"As much as possible, if we could avoid the bellicose semantics and come back to a reasonable discussion that would help for economic confidence," he said.

The French economist admitted that the current exchange of words and policy decisions between the U.S. and its trade partners are already having a negative impact on the global economy.

"We've obviously seen stock prices going down, some risk premia going up, so some tightening of financial conditions globally, starting with the U.S. But it all depends on how the situation will evolve and that's certainly what we don't want to see — a general tightening of financial conditions," he said.

Coeure added that the current trade tensions are the "biggest" concern that the ECB has at the moment.