Nato chief Anders Fogh Rasmussen has called for a new missile defence system that would protect the US and its allies, and include Russia as well, BBC reported.
Mr Rasmussen said the threat of missile proliferation was real and growing and, in cases such as Iran, these missiles could threaten Nato territories.
He said missile defence could bring Nato and Russia together.
Mr Rasmussen was speaking at the Brussels Forum - an international gathering in the Belgian capital.
The Nato secretary general said he saw a new Euro-Atlantic missile defence system, as he called it, as more than just a means of defending Nato countries against ballistic missile attack.
Mr Rasmussen clearly believes that such a system could re-invigorate not just the European allies' relationship with the US but also Nato's whole relationship with Russia.
"It would be an opportunity for Europe to demonstrate again to the United States that the allies are ready and willing to invest in the capabilities we need to defend ourselves," he said.
But he also argued that such a step would create a new dynamic in European security.
It would be a strong political symbol that Russia is fully part of the Euro-Atlantic family, he said.
It's a bold proposal. The US has tried to draw Russia into its missile defence plans with very limited success.
Moscow tends to see the proposal as ultimately undermining its own nuclear deterrent.
But Nato as a whole is increasingly interested in such defences and looks set to go ahead with them with or without Russia on board.