During his time in office, Trump privately threatened several times to withdraw the US from NATO, describing the alliance as an “obsolete” organization, Ednews reports via Sputnik.

European countries must prepare for a scenario in which the US leaves NATO under a possible new presidency of Donald Trump, unnamed diplomats from the alliance's member states have told The Telegraph.

The diplomats were referring to Trump's warning last month that he would encourage Russia to attack any NATO member that didn't meet the alliance's defense spending guidelines.
 
One official expressed concern over Trump’s comments, adding that "Nobody knows what he’s going to do next."

The diplomat added that the number of nations meeting the NATO target to spend 2% of gross domestic product (GDP) on defense had risen significantly, so those members could tell Trump "he’s getting what he wanted."
 
Another official said that Trump’s comments highlighted that "we [NATO members] are so over-dependent on the US." The source noted that a "discussion" about how to hedge against the risk of US exit from NATO was "necessary."
 
NATO members need to take more of a lead in European security because if "the US pulls out there will be a massive gap," according to the official.

The third diplomat insisted that NATO members must “do the planning” and reconsider defense capabilities due to threats by Trump.

'You Got to Pay Your Bills'

Speaking at a rally in South Carolina in February, the 45th US president argued that "NATO was busted until I came along."
"I said, ‘Everybody’s gonna pay.’ They said, ‘Well, if we don’t pay, are you still going to protect us?’ I said, ‘Absolutely not.’ They couldn’t believe the answer,” per the former US leader.
Trump then added that "one of the presidents of a big country" at one point asked him whether the US would still defend the country if they were invaded by Russia even if they "don’t pay."
 
"No, I would not protect you. In fact, I would encourage them to do whatever the hell they want. You got to pay. You got to pay your bills," Trump recalled telling that president.
 
The key Article 5 of NATO’s treaty pertains to the promise of the so-called collective defense, stipulating that an attack on one member nation is an attack on all the nations in the alliance.