"I totally stand by raising these ambiguities because I believe it was irresponsible of us to keep talking about financial and technical matters given the stakes we currently face," Macron said at a joint news conference after the talks.

"A wake-up call was necessary," he said, regarding NATO's failure to address pressing challenges such as relations with Russia, the subject of Turkey, or even "who is the enemy?"

It is no longer Russia or China, Macron said: "Our common enemy... is the terrorism which has struck us all."

Macron's "brain death" comment, published in an interview with the Economist magazine this month, drew sharp criticism from allies, not least Stoltenberg, who warned against undermining the transatlantic alliance.

Stoltenberg said Thursday that "in uncertain times, we need strong multilateral institutions like NATO," and that he had "good and open discussions" with Macron.

He praised in particular France's role in fighting the spread of Islamic terrorism in the Sahel region of Western Africa, which saw the death of 13 French soldiers in Mali this week when two of their helicopters collided while engaging with insurgents trying to flee.

Macron said that at next week's NATO meeting in Watford, northwest of London, that he would urge allies to get more involved in the Sahel fight.

While Britain has provided helicopters and security personnel to help France's 4,500-member Barkhane force in West Africa, and the US provides intelligence support, Paris has so far failed to persuade other allies to make a significant contribution.

Macron also said he would begin an in-depth review of Barkhane with "all options on the table".

Underscoring that France's forces were acting "on behalf of everyone", he said: "A bigger engagement by the allies is obviously something that would be quite positive."

Speaking later to Europe 1 radio Stoltenberg said that if Macron requested NATO's help the alliance would consider the appeal "very seriously".

- Russia row -

Macron on Thursday also defended his push for a rapprochement with Russian President Vladimir Putin, rebuffing charges of naivety.

"Has the absence of dialogue with Russia made the European continent safer?... I don't think so," he argued.

In a controversial move, he suggested talks with Moscow over its call for a moratorium on deploying mid-range nuclear missiles in Europe.

The proposal came after the US walked away from the 1987 Intermediate-Range Nuclear Forces (INF) treaty with Moscow earlier this year, leading Moscow to also suspend its participation.

NATO diplomats have voiced concern about even considering Russia's request to freeze the status quo, pointing out that it would give Moscow, which has already deployed the missiles, a military advantage, over NATO, which has not.

Macron said he "absolutely did not accept the moratorium proposed by Russia" but considered it a basis for discussions.

He also insisted that European nations must be involved in any efforts to forge a new pact limiting mid-range nuclear missiles.

"We cannot delegate our security to a bilateral accord where no European is a stakeholder," Macron, who wants to less Europe's defence dependence on the US, said.

The comments set the stage for another possibly fractious NATO summit in London on December 3-4, which will be attended by US and Turkish presidents Donald Trump and Recep Tayyip Erdogan.

Last year's gathering got off to a stormy start, with Trump calling Germany a "captive" of Russia and demanding that NATO members double their defence spending.

This year's meeting looks set to be overshadowed by the US and Turkey's go-it-alone approaches to Syria.

Turkey's offensive against Syrian Kurdish forces in northern Syria -- launched after receiving a green light from Trump, who ordered a surprise withdrawal of US troops -- caught NATO allies by surprise in October, and largely contributed to Macron's damning critique of the alliance.

Trump in turn has repeatedly accused European NATO members of freeloading on the US by falling short of their commitment to spend at least two percent of GDP on defence.

Stoltenberg reiterated that all alliance members were increasing their defence outlays.

He also confirmed that Washington would cut its funding to the alliance's operating budget to 16 percent of the total from 22 percent, with Germany and other nations taking up the slack.

Macron was dismissive of the budget debate.

"If some people want to see an example of what they term 'cost-sharing', they can come Monday to the ceremony France is organising" for the 13 soldiers killed in a midair helicopter collision while fighting insurgents in Mali, he said.

"There they will see the cost."