"America is more than a one-man show. Anyone who continues to pour oil on the fire in a situation like this is acting irresponsibly," Maas told Germany's Funke media in unusually blunt language.

"Now is the time to keep a cool head until an independently determined result is available," he added in some of his first comments on the situation.

"In order for the result - which has not yet been determined - to be accepted, everyone must first show restraint," Maas told Funke media in an interview, extracts of which he tweeted. "That includes us."

"Decent losers are more important for the functioning of a democracy than radiant winners," he added.

Maas said he expected that once the election result is settled, "the USA will probably not return to the international stage with full energy for the time being", but he added: "The world needs the USA as a force for order, not as a factor of chaos."