NATO chief Jens Stoltenberg has denied the military alliance is expanding northwards to counter new threats.
It comes as the organisation holds its biggest military exercise since the Cold War near Norway’s border with Russia.
But Stoltenberg told Euronews the drills — which involve 50,000 troops, 250 aircraft and 10,000 tanks — were not targeting any particular country.
“No [NATO is not expanding northwards],” he said. “It has always been northern, Iceland and Norway are among the founding members. We have to be able to respond to any threat from any direction: north, south, east, west.
“NATO has to be able to move heavy equipment, supplies and thousands of soldiers to reinforce any ally if needed.
“The reason we do that is not to provoke a conflict but to prevent one. As long as a potential adversary knows NATO is there to defend all allies — and that an attack on one ally will trigger a response from the whole alliance — then we prevent conflict, which is the main task of NATO.”
Critics say the build-up will stoke tensions with Russia, which last month held its largest-ever military exercises.
Stoltenberg denied the manoeuvres were linked to Russia’s annexation of Crimea or US claims it had broken a nuclear arms limitation treaty.
"Russia will observe the exercise, because we have nothing to hide,” he added. “We are open and transparent when it comes to our exercises.
“This exercise is not directed against any specific country, the purpose is to make sure that NATO continues to be able to deliver deterrents to prevent conflict."
You can watch more of Euronews' interview with Stoltenberg in the video player, above.