NATO Secretary General Jens Stoltenberg warned Thursday that Europe's defence depends on close transatlantic bonds and not on a quest for the continent's strategic autonomy.

Most EU member states are also NATO member states, and their citizens' safety relies on an alliance that far outspends their own capitals on security, he argued.

In an interview with AFP, after an address at the College of Europe in Belgium, Stoltenberg said he welcomed Brussels' efforts to boost spending and streamline its defence industry.

But he was dubious about calls for the continent to develop "strategic autonomy" of the kind championed by France's President Emmanuel Macron.

The European Union doesn't have an army of its own, but the European Commission is seeking what it calls a more "geopolitical role", with its own foreign and defence industry policy.

Fellow Brussels-based institution NATO, by contrast, bills itself as the most successful military alliance in the world -- in large part thanks to American military spending.

"I support EU efforts on defence, because more defence spending, new military capabilities and addressing the fragmentation of the European defence industry -- all of that will be good for European security, for transatlantic security, for all of us," he told AFP.

"So all these efforts -- as long as they complement NATO -- we welcome them, but the EU cannot defend Europe."

"More than 90 percent of the people in the European Union, they live in a NATO country. But only 20 percent of NATO's defence spending comes from NATO EU members," Stoltenberg said.

Under the previous US president, Donald Trump, transatlantic ties frayed.

Trump repeatedly accused the European allies of not pulling their weight, and Macron in turn accused NATO of failing to adapt to Europe's security priorities-- famously branding its strategy as "brain dead".

There have also been tensions between European capitals and NATO ally Turkey, which is accused of breaking a UN arms embargo on Libya and violating Greek waters in a search for gas reserves.

During this period Britain, a major NATO member, left the European Union, further tipping the balance of spending between EU and non-EU allies in the latter's favour.

NATO Secretary General Jens Stoltenberg said in an interview with AFP that he welcomes EU efforts to boost its defence industry
NATO Secretary General Jens Stoltenberg said in an interview with AFP that he welcomes EU efforts to boost its defence industry AFP / JOHN THYS

This has fuelled calls from some in Europe for the continent to chart its own strategic course.

Macron told the Financial Times last month: "I am a defender of European sovereignty, of strategic autonomy, not because I'm against NATO or because I doubt our American friends, but because I am lucid on the state of the world.

"Nobody can tell me that today's NATO is a structure that, in its foundations, is still pertinent. It was founded to face down the Warsaw Pact. There is no more a Warsaw Pact," he said.

The Warsaw Pact was signed in 1955 to form a Soviet bloc counterpart to NATO, which was created six years earlier.

But Stoltenberg says NATO still faces many other foes.

He cited Russia's encroachment on its neighbours, international terrorism, cyberattacks, the security impacts of climate change, and the need to maintain an advantage over rising China.

Stoltenberg, the 61-year-old former prime minister of non-EU NATO member Norway, prefers the term "strategic solidarity" to "strategic autonomy".

"I don't believe in Europe alone. I don't believe in North America alone. I believe in North America and Europe together in strategic solidarity in NATO," he said.

"Because I don't believe that any country or any continent alone can manage the security challenges we face today."

In geographic terms, he points out, the European Union's flanks are defended in the north Atlantic from Russian encroachment by non-EU members the US, Canada and the UK.

In the southeast, non-EU member Turkey -- often criticised as a threat to stability by Paris and Athens -- sits on the borders with Syria and Iraq and is "extremely important in the fight against Daesh (the Islamic State group), international terrorism."

US President Joe Biden, expected to attend a NATO alliance leaders' summit later this year, is seen as wanting to keep pushing European members to meet their defence spending commitments -- as Trump did.

"But most importantly, this is about politics," Stoltenberg said. "Because any attempt to weaken the link, to divide Europe and North America, will not only weaken NATO, it will divide Europe."