Failing to open communication channels with Moscow would be a "huge mistake", Macron said, despite suspicions from Poland and other former Soviet-bloc states in the EU.
French President Emmanuel Macron attends a joint news conference with China's President Xi Jinping at the Great Hall of the People in Beijing, Wednesday, Nov. 6, 2019.
Trump also wrong-footed the allies by announcing a troop draw-down in Afghanistan and then declaring that peace talks with the Taliban were cancelled after a bomb attack killed a USA soldier.
But in Thursday's interview he appeared to go further, calling for a wholesale change in Europe's security architecture, in which NATO's future role was unclear.
Beyond that, the USA leader publicly berated other leaders at a May 2017 summit for failing to boost their military budgets. It spends more on its defense budget than all the others combined.
Pointing to what she described as Macron's "drastic words", Merkel said the transatlantic military pact was "indispensable" for European security.
Macron said the European members of the 29-nation alliance "should reassess the reality of what North Atlantic Treaty Organisation is in the light of the commitment of the United States". His decision to pull the US out of the Paris climate agreement particularly annoyed Macron.
"Because what all this shows is that we need to reappropriate our neighborhood policy, we can not let it be managed by third parties who do not share the same interests", Macron said in the interview. If we don't wake up ... there's a considerable risk that in the long run we will disappear geopolitically, or at least that we will no longer be in control of our destiny.
Mr Stoltenberg said in reference to the 30th anniversary of the Berlin Wall falling: "The reunification of Germany and Europe would have been impossible without the United States's security guarantee".
Stoltenberg backed her up, declaring "European unity can not replace transatlantic unity", and warning that the EU can not defend Europe without outside assistance.
U.S. Secretary of State Mike Pompeo, when asked about Macron's comments Wednesday, said "NATO remains a critical, perhaps historically one of the most critical strategic partnerships in all recorded history", according to Reuters.