Its the same all over the world. With expectations of Central Bank rate cuts over the next several years.
It is not only the USA that has a sagging yield curve, almost country with a powerful Central Bank has a sagging yield curve. As an example, this chart compares the USA (blue) with Canada (green) and the UK (red). Japan (orange). Denmark (green) and Germany (purple) have sagging curves that are also negative at tenors of less than 15 years. If we believe the expectations model of the yield curve, we are expecting interest rate cuts for 3-5 years.
Now turning to Latin America. Of course, Venezuela (blue) is steeply downward sloping along with Argentina (green). Chile, Mexico and Brazil maintain normalized yield curves. Venezuela and Argentina are examples are liquidity models of the yield curve.
Lastly, there is the preferred habitat theory where Central Banks like The Federal Reserve, the ECB and Bank of Japan reside … with a vengeance .. at the short-end of the yield curve.