European governments called for cool heads and tighter unity as they reacted with shock to President-elect Donald Trump's remarks slamming NATO and predicting European Union nations would follow the U.K. out of the bloc.

Trump's comments, which call into question the depth of continued U.S. support for free trade and European defense, sent shock waves around the EU at a time when governments are already battling to deal with the rise of nationalism, Brexit and a belligerent Russia.

"If the Europeans want to be protagonists, and not just spectators, they have to work closer together and accelerate on a common security and defense policy," Sandro Gozi, Italy's junior minister for European Affairs, said in an interview. "I don't share his prediction that there are other Brexit-type departures from the EU on the horizon."