German Foreign Minister Frank-Walter Steinmeier said he was perplexed by US president-elect Donald Trump's comments that connected life under Adolf Hitler with the publication of unverified reports of allegedly damaging Russian intelligence about him.

Trump lashed out Wednesday on Twitter at those who allegedly leaked the claims, asking: "Do we live in Nazi Germany?"

"I am as puzzled as you are with regard to the comparison with Nazi Germany," Steinmeier told reporters in Berlin.

Steinmeier was equally mystified about the shape of US foreign policy once the New York real estate magnate moves into the White House, questioning whether from Trump's preference for communicating with Twitter was the best way to present the new president's world view.

So far, Steinmeier said he could not recognise any foreign policy concept from Trump and his planned new administration.

"I cannot imagine that this is going to happen in the long run over Twitter," said Steinmeier.

"In any case, I would not be able to formulate a foreign policy concept in 140 characters," he added.

- dpa