National Security Council spokesperson John Kirby announced on Wednesday that the United States was investigating reports substantiated by The Washington Post and two human rights organizations indicating that the Israeli occupation utilized US-made and supplied white phosphorus shells in an attack on southern Lebanon.

The top white house official acknowledged a lack of complete transparency and visibility regarding the reported incidents involving white phosphorus usage in Lebanon. He stated that efforts were underway to gather more information, emphasizing ongoing inquiries with the Israeli regime to verify the accuracy of the reports. 

"We're looking into that…We're asking more questions of our Israeli counterparts about those reports to see if they're accurate and how if white phosphorus was used, how it was used," Kirby told CNN.

A Washington Post report that came out on Monday said the Israeli occupation used white phosphorus munitions handed to it by the US against Lebanon in October.

According to WashPo, the US-based newspaper got its hands on shell fragments found in al-Dhayrah, southern Lebanon, namely the remanent of three 155mm artillery rounds that injured at least nine civilians in what should be classified as a war crime.

A Washington Post journalist said production codes found on the shells match those by the US military to categorize domestically-produced munitions. One of the shells clearly has "WP" printed on it, which is consistent with white phosphorus rounds, arms experts said.

According to Pentagon spokesperson Pat Ryder on Wednesday, the US Department of Defense (DoD) is not formally reviewing the Amnesty International report about Israeli use of white phosphorus weapons in the Gaza conflict.

"While DoD is not conducting a formal review, the Civilian Harm Mitigation Response team will consider the report along with other publicly available information related to civilian harm as they carry out their responsibility to advise senior DoD leaders. We have no further specifics to offer about the report at this time," Ryder said in a statement.

Proudly US-made, supplied

The internationally prohibited munition is part of multi-billion arms packages that the United States sends to the Israeli occupation, fueling the ongoing genocide in Gaza that has killed more than 18,000 Palestinians, at least half of whom are children.

Kirby, however, said white phosphorus had a "legitimate military utility", namely illumination and concealing movements.

"Obviously any time that we provide items like white phosphorous to another military, it is with the full expectation that it will be used in keeping with those legitimate purposes ... and in keeping with the law of armed conflict," he said.

Amnesty International underlines the incident should be investigated as a war crime. Although the Israeli occupation claims it was using the munition as a smokescreen, white phosphorus fell onto several homes and ignited wildfires, as well as wounded civilians, with black chemicals still being on the ground 40 days after the fact. Residents have reported that these chemicals combusted when they kicked them, which again proves that it is white phosphorus.

What does white phosphorus do?

White phosphorus, with its dual capability for marking, signaling, and obscuring or as an incendiary weapon, can cause severe burns to individuals and ignite structures, fields, and other civilian objects in the vicinity.

White phosphorus is a combustible (ignites when exposed to oxygen) and a severely fatal chemical. The combustible reaction produces light, heavy white smoke, and heat of about 815°C. 

White phosphorus is highly soluble in human flesh and causes deadly thermal and chemical burns that can go as deep as the bones. 

Direct contact is extremely excruciating and can leave long-lasting damage to internal organs. Even inhaling its vapor can cause severe inflammation in the trachea.