Trumps talks of NATO problems go back to his last term. Foreign leaders showed fear of reduced US cooperation then [1], some directly attributing increased spending to that [2]. It was very widely reported back then, with similar fervor.

[1] https://www.nbcnews.com/politics/2016-election/donald-trump-...

[2] https://www.nytimes.com/2016/07/22/world/europe/donald-trump...