There are ~2 million indigenous Americans scattered around the country from many different tribes, nations, and ethnic groups. The us is still using a lot of it’s old colonial systems, for example the “blood quantum” system, intended to exterminate indigenous Americans as a distinct culture. Indigenous Americans are also trapped in conditions of extreme poverty due to both historic and contemporary policies that are de facto social murder. It’s a big, awful, complex issue due to how many different groups of indigenous people their are, the us’s patchwork of quasi-independent states, and all sorts of other stuff but if you stand back far enough it’s genocide.

For Yemen, you’d want to look at the US/Saudi war against the Houthis that started back during Obama/Biden. The Saudis couldn’t win a fist fight with a drunk card board box let alone fight Ansarallah on the ground. So they went with extermination by destroying food, water, and medical infrastructure to spread disease and starvation. It’s the quickest way to murder huge numbers of people, especially children.