United Nations chief Antonio Guterres on Tuesday urged Israel not to invade southern Gaza’s Rafah city, after the Israeli prime minister said an offensive would go forward regardless of a pending hostage deal with Hamas. With the war roiling the region, international outrage mounting over the human toll, and mediators ramping up diplomatic efforts to ease the crisis and reach a truce, Guterres implored Israel not to go ahead with its operation. “A military assault on Rafah would be an unbearable escalation, killing thousands more civilians and forcing hundreds of thousands to flee,” the secret…