** Shares of exchange-traded funds tracking U.S. Treasuries rise as escalating trade war sends yields tumbling US/

** U.S. Treasury yields, which move inversely to prices, fall as investors flee to safe-haven assets after China announces tariffs of 34% on U.S. goods

** iShares 20+ Year Treasury Bond ETF TLT.O jumps 1.7%, set for best session since November and trading at a near four-month high

** iShares 7-10 year Treasury Bond ETF IEF.O rises 0.4% to highest since October; yield on benchmark U.S. 10-year Treasury US10YT=TWEB falls to six-month low

** iShares U.S. Treasury Bond ETF GOVT.Z gains 0.4%, also to highest since October

** On the other hand, iShares iBoxx high-yield corporate bond ETF HYG.P, which tracks riskier company debt, drops 1.6% and set for worst day since December as spreads of HY bonds over U.S. Treasuries surge to highest since November 2023

** Including Friday's moves, TLT fund up 7% year-to-date

(Reporting by Lisa Mattackal)