The Biden administration expressed concern about the possibility Israel's military used U.S.-provided white phosphorus in an attack in Lebanon that injured at least nine civilians.

Israel reportedly fired 155 millimeter artillery rounds of white phosphorus into the community of Dheira in October, which is near the Lebanon-Israel border, in which at least nine people were injured, the Washington Post reported on Monday.

COP28 DRAFT TEXT STOPS SHORT OF CALLING FOR PHASEOUT OF FOSSIL FUELS

"[We're] certainly concerned about that. We'll be asking questions to try to learn a little bit more," National Security Council coordinator John Kirby said during a Monday press gaggle.

White phosphorus burns at high temperatures and can stick to skin, causing significant burns and respiratory damage, though its intended use is largely to produce smoke to provide cover for battleground movement.

"I do think it's important to remind that white phosphorus does have a legitimate military utility in terms of illumination and producing smoke to conceal movements," he added. "Anytime that we provide items like white phosphorus 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."

The specific shells used in the attack, which the Washington Post recovered, had production codes that match the nomenclature of the ones the U.S. military uses, while those markers indicate they were made in 1989 and 1992, respectively.

The U.S., which has provided military aid to Israel since the war between it and Hamas erupted on Oct. 7, has "not provided white phosphorous rounds to Israel since October 7th," Pentagon spokesman Maj. Gen. Patrick Ryder said on Monday. "I can't verify whether or not the rounds identified in this story were provided by the United States."

The allegation civilians were harmed by Israel's use of white phosphorus comes as it has faced significant international scrutiny for the thousands of civilian casualties in Gaza in only two months of war. The death toll is believed to exceed 17,000 people, according to the Hamas-controlled Gaza Health Ministry, while an Israel military spokesman said it's believed that two civilians have been killed for every terrorist that has been killed.

Israel and Hezbollah, a terrorist group based in Lebanon, have repeatedly engaged in tit-for-tat exchanges of rocket fire since the war broke out, though both sides have refrained from escalating it to a full-on conflict.

CLICK HERE TO READ MORE FROM THE WASHINGTON EXAMINER

The Second Lebanon War was fought between Lebanon and Israel and ended in 2006 with United Nations Security Council Resolution 1701, which barred Hezbollah from maintaining a military presence south of the Litani River, which is located about 18 miles north of the Israel-Lebanon border. Hezbollah has largely violated the resolution, while Israeli Defense Minister Yoav Gallant warned last week that Israel will “act with all the means at its disposal” to push Hezbollah away from its border.

"We absolutely don't want to see this conflict spill over into Lebanon," Kirby added. "We don't want to see a second front. We don't want to see it escalate and widen."