Memes

The US has been around just as long as a civilization. If the Chinese get to claim credit for the radically different ancient predecessors to modern China, then the US can claim decent from both the ancient Native American civilizations

The US is a settler colonial project that carried out an extermination campaign and genocide of hundreds of native tribes, and stole their land. Settlers have no right to claim descent from the people (they're still) trying to exterminate. Unlike South America, there's not even a genetic heritage; the US colonialist just killed every indigenous person they found, or put them into reservations.

Neither the PRC nor most ME countries are settler ones. The number of settler-colonial countries is tiny: the US, Canada, Israel, Australia, New Zealand, are the main ones.