Despite what it, and others, may think, the USA is not NATO; that's what consensus is all about.That might make some sense with the double-negative removed!
That will then illustrate the fallacy of your statement.
The USA has said “NO!” to the purchase/instillation of S-400, by Turkey . . . .
. . . . it STILL happened .
Jens Stoltenberg [NATO Secretary General]: 'It is a national decision what kind of systems different NATO Allies procure, but we fully realise that this is now a challenge and it is an issue that has been discussed is addressed by the United States and Turkey.' 'I hope that it's possible to find a solution to this issue, because we see now that this is an issue where there is disagreement between two Allies; Turkey and United States.'
JENS STOLTENBERG [NATO Secretary General]: 'It is the decision by every NATO Ally what kind of military equipment they buy.'
E2A: 2nd link