US Secretary of State Mike Pompeo has warned of the dangers posed by Russia and China and called on Nato to grow and confront “the challenges of today”.
On a visit to Berlin, Mr Pompeo said methods used by China to suppress its own people would be “horrifyingly familiar” to East Germans.
And he accused Russia of invading its neighbours and crushing dissent.
He laughed off comments from French President Emmanuel Macron, who said recently that Nato was “brain dead”.
However, Mr Pompeo told reporters: “Seventy years on… it needs to grow and change. It needs to confront the realities of today and the challenges of today.
“If nations believe that they can get the security benefit without providing Nato the resources that it needs, if they don’t live up to their commitments, there is a risk that Nato could become ineffective or obsolete.