By Nidal al-Mughrabi and Bassam Masoud CAIRO/GAZA (Reuters) -The United Nations on Tuesday demanded an immediate humanitarian ceasefire in the Gaza Strip as U.S. President Joe Biden warned Israel it was losing international support because of its “indiscriminate” bombing of civilians in its war against Hamas militants. After dire warnings by U.N. officials about a deepening humanitarian crisis in Gaza, the 193-member U.N. General Assembly passed a resolution calling for a ceasefire with 153 countries voting in favour and 23 abstaining. The U.S. and Israel, which argue a ceasefire only benefits…