NATO membership open to nations meeting standards: Obama

US President Barack Obama Friday said NATO will defend every ally, while reaffirming that the door to NATO membership remains open to nations that can meet its "high standards".

He made the remarks here at a press conference following his formal discussions on security issues with leaders of NATO member states on the final day of the bloc's summit in Newport, Wales of Britain, Xinhua reported.

"Here in Wales, we also sent a strong message to Russia that actions have consequences," he said, adding that NATO's alliance "is fully united in support of Ukraine's sovereignty, independence and territorial integrity".

On the rise of the Sunni militant organisation Islamic State (IS) (formerly called ISIL), he said: "NATO allies and partners are prepared to join in a broad, international effort to combat the threat posed by ISIL."