Will likely come into effect - only the day, the UN members decide to abolish the Veto right of those UN veto buggers.
Till then why on earth should the USA abandon it's
prime seat in regards to directing - manipulating all those global issues - that serve foremost the ultimate interests of the USA and it's crucial preservation of global hegemony ??
A respective bill needs to be ratified by the US Senate and Congress.
The bill requires:
the President to terminate U.S. membership in the United Nations (U.N.), including any organ, specialized agency, commission, or other formally affiliated body; and the closure of the U.S. Mission to the United Nations.
Even St. Donald wouldn't be so moronic as to throw away the USA's main tool. (Additionally the elitist circles that sponsor, brought in Trump and keep him in "presently" into US politics, will certainly never agree). Otherwise he will face the same fate as JFK.
It ls beheld in his lying human scumbag nature - that he will off course "promise" as usual, any move/policy that might bring in naive voters.
He discarded the US membership in the WHO and the UN HRC - since these two UN charters only bring in "obligations" for the USA - and even make it possible for the UN to condemn and punish US actions. Same goes for e.g. the Paris climate accord - that however was rejoined by Biden.