I saw this between 1996 and 2006 for sure. It was a short term video (maybe an episode? I already searched in Outer Limits, Twilight Zone and alike with no luck)
It was about an alien warning, posing humanity some kind of dilemma: If we deliver some humans for them, they would allow the rest to continue living, if we refuse to cooperate, we all would die.
I think (but not sure) that there was some kind of UN scenery (some tribute to "To Serve Man" for sure) and media coverage about what would our final decision be; I remember a final view of an UFO over a building or skyscraper with some kind of ray for people being abducted/delivered.
The main thing was the dilemma for us whether to adapt and survive through betrayal or refuse and perish.