"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 press conference after the talks.

"A wake-up call was necessary," he said.

Macron's 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 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 is acting "on behalf of everyone".

"In this context, and in light of the decisions that France will take, a bigger engagement by its allies is obviously something that would be quite positive," he said.

- 'Cost-sharing' -

Macron also defended his move to try to establish a working relationship with Russian President Vladimir Putin, which has riled EU leaders who have shunned Moscow since its annexation of Crimea from Ukraine.

"We want a lucid, robust and demanding dialogue with Russia, with neither naivety nor complacency," Macron said.

He also said European nations must be involved in any talks to forge a new pact limiting mid-range nuclear missiles held by the US and Russia, after a landmark Cold War-era accord fell apart this year.

Russia has called on the US and other NATO member to implement a moratorium on deploying medium-range missiles, something Stoltenberg has so far ruled out.

"An accord that would replace the INF... requires the involvement of Europeans," Macron said. "It's a question of the security of Europe."

"We cannot just content ourselves with bilateral treaties," he added.

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.

Turkey's move against Syrian Kurdish forces in northern Syria -- after getting a green light from Trump -- caught NATO allies by surprise, and largely contributed to Macron's damning critique in the Economist interview.

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

But Macron said that "our common enemy is the terrorism that has struck us all."

"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."