An Israeli strike in Gaza that killed seven aid workers for the non-profit World Central Kitchen has touched off fury and indignation inside the White House, prompting President Joe Biden on Tuesday to release a public statement using a word he has rarely invoked over the course of the conflict that has been filled with endless tragedy: "Outraged." The deaths of the workers who were attempting to deliver food to starving civilians in the besieged enclave – including one dual US-Canadian citizen – has raised the frustration for Biden and his top officials to a new level, a senior administration official told CNN. Biden's statement Tuesday evening that mourned the deaths of the seven workers included some of the most fiery and blunt language from the president since the start of the Israel-Hamas war in October. He explicitly blamed Israel for failing to protect aid workers and civilians, and he said, "Incidents like yesterday's simply should not happen." The strike on the World Central Kitchen workers has been a "standout incident" as far as the Biden White House is concerned, the official said, prompting serious consternation and concern in what had already been a moment of high tensions between the US and Israel. The president discussed the deaths of the workers with a small group of Muslim community leaders at the White House Tuesday, according to one of the attendees. Some of the participants were doctors who have spent time in Gaza and have seen first-hand the plight of the Palestinian civilians there. One of them, CNN reported, walked out of the meeting early in a show of protest. "The president expressed that this is a very difficult situation and that he would like to see an end to this war," said Salima Suswell, founder of the Black Muslim Leadership Council. "The conversation was difficult at moments." Asked about Biden blaming Israel for failing to protect civilians and aid workers in his statement, a senior adviser to the president told CNN: "It's what he wanted to say." Israel has said it will investigate why the aid workers' vehicles were hit by Israeli airstrikes, and Biden called on the probe to be "swift" and "bring accountability." — CNN