U.S. Treasury yields slipped on Thursday as safe-haven bids increased due to news of a Russian missile attack on Ukraine and mixed economic data showing the slowing of the U.S. economy. The yield on benchmark U.S. 10-year notes fell to 4.382%, while the U.S. two-year note yield slipped to 4.298%. The U.S. yield curve flattened, with the gap between two- and 10-year yields at 8.4 bps. Investors are also closely watching for clarity on President-elect Donald Trump's policies and the next Treasury secretary.