Brussels: Britain will remain a strong ally and continue to play a leading role in NATO despite its vote to leave the European Union, alliance head Jens Stoltenberg said Friday.
"The UK will remain a strong and committed NATO ally and will continue to play its leading role in our alliance," Stoltenberg said in a statement.
He said NATO would also provide a platform for continued cooperation between its European member states in the face of new security challenges.
"Today, as we face more instability and uncertainty, NATO is more important than ever as a platform for cooperation among European allies, and between Europe and North America," he said.
"The alliance remains committed to closer cooperation with the European Union," he added.
Some 22 of the 28 EU nations are also NATO member states.
Stoltenberg told reporters separately that he was concerned "about a more fragmented Europe but it is important now to look forward and work on how we can strengthen cooperation."
He said British Defence Secretary Michael Fallon had phoned him earlier Friday to offer assurances the London "was not only committed to NATO but also to NATO-EU cooperation."
NATO leaders meeting in Warsaw next month are due to issue a full-dress statement on enhanced cooperation with the EU, he noted.
Britons voted 52 percent to 48 percent to leave the EU on a groundswell of resentment at what was seen as Brussels` interference in key aspects of daily life.
Britain, nuclear armed and wielding veto powers in the UN Security Council, has had a major say in EU foreign and defence policy.
It has jealously guarded its sovereign right to decide what it does with its own military, shooting down any suggestion that the EU could one day have an army of its own.