U.N. Secretary-General Antonio Guterres on Tuesday appealed to Israel and Hamas to spare no effort to get a truce deal and warned Israel that an assault on Rafah would "be a strategic mistake, a political calamity, and a humanitarian nightmare."

He also called for crossings into Gaza to be reopened immediately.

"I am disturbed and distressed by the renewed military activity in Rafah by the Israeli Defense Forces," he said. "The closure of both the Rafah and Karem Shalom crossings is especially damaging to an already dire humanitarian situation. They must be re-opened immediately."

(With input from agencies)