Col Kale, 46, was from the western Indian state of Maharashtra and had joined the UNDSS in Gaza weeks before the attack. This was his first deployment in the region.
“He told me that he had joined the UN because it seemed like the best way to make a difference,” Gilles Michaud, the Under-Secretary-General for Safety and Security, said in a statement.
“He signed up to work in support of people who desperately need help; in the most dangerous place, at a time of unimaginable crisis. This speaks volumes about his character,” he said.
Kale had spent 22 years in the Indian army before he opted for an early retirement; he later worked in a private firm, his family told BBC Marathi.
But unhappy with a desk job, he joined the UNDSS in April.
“Waibhav Kale, an Indian, had nothing to do with Hamas or Israel or this war. But he has sacrificed his life for peace. Now, peace must be restored in Gaza,” his cousin Chinmay Kale told local media.
India’s mission to the UN in New York said its “deepest condolences are with the family” of Col Kale.
UN secretary-general António Guterres said on Monday that he was “deeply saddened” to learn of the worker’s death and sent his condolences to their family, Mr Farhan Haq said in a statement.
In a separate statement, Mr Guterres said more than 190 UN staff had been killed in Gaza since the war began.
Apart from Col Kale, six international aid workers and a Palestinian colleague from the international food charity World Central Kitchen were killed in an Israeli strike at the start of April.
Their deaths sparked an international outcry and the IDF sacked two senior officers over the incident which it described as a “grave accident”.
Israel launched a military campaign in Gaza with the stated aim of destroying Hamas – which controls Gaza – in response to the group’s cross-border attack on southern Israel on 7 October, during which about 1,200 people were killed and 252 others were taken hostage.
More than 35,090 people have been killed in Gaza since then, according to the territory’s Hamas-run health ministry.
Additional reporting by Malu Cursino in London
