Oct. 16 (UPI) -- The United States has warned Israel that it must take "concrete measures" to improve a worsening humanitarian crisis in Gaza within 30 days or risk losing military assistance provided by Washington. The demand came in a letter from Secretary of State Antony Blinken and Defense Security Lloyd Austin to Israeli Defense Minister Yoav Gallant and Strategic Affairs Minister Ron Dermer expressing deep concern at the "increasingly dire humanitarian situation" facing more than 2